Colonel Jack O'Neill is brought out of retirement to lead a new expedition back to Abydos, only to find an old friend, a new enemy and a far wider use of the Stargate.

The team, now designated SG-1 are planning their next foray through the gate as they try to map out the variety of sites available to them and locate their missing friends. O'Neill asks that Teal'c be allowed to join his team but Gen. Hammond thinks that will be unlikely given that he is the host for a Goa'uld. Unknown to anyone, however, is that O'Neill's close friend, Maj. Charles Kawalsky, leader of SG-2, has been infected by a Goa'uld, an immature version that has not yet taken complete control of the host. Kawalsky is having regular blackouts during which the Goa'uld is trying to return to the gate. An MRI reveals what is wrong but it's unlikely the creature that has fused itself to Kawalsky's spine can be surgically removed. Meanwhile, Col. Kennedy arrives to question Teal'c who has pledged his loyalty to his new world.

While exploring a world populated by Mongol descendants, Capt. Carter is abducted for a wife of a local warlord.

The Stargate base is put in deadly peril when it is contaminated with a dangerous infection which causes its victims to become mindlessly animalistic brutes.

The SG-1 team is sent after the SG-9 team that has failed to return. They find that SG-9's captain, having been treated like a god by planetary inhabitants, is drunk with power and is tyrannizing them. Can they overcome him?

When Jack is injured unintentionally by a crystal alien, the alien duplicates Jack's form and out of fear of retribution tries to heal Jack. He returns to Earth in place of Jack, while Jack is still unconscious on the planet, to find the one thing he feels will accomplish this; the one thing that cannot be found again. Meanwhile, the 'real' Jack has returned and is trying to convince SGC that he is who he says he is.

With the Stargate program in danger of being terminated, the team is under pressure to find technology. Visiting a planet where they believe there is a creature that possesses the secret of invisibility, they encounter Apophis and his guards. Both sides receiving mortal wounds, they are aided by the planet's inhabitants, the Nox, a gentle people with a very large secret.

On the planet Argos, Kynthia seduces Colonel O'Neill, which gives him an Argosian lifespan of only a 100 days. As he begins to age rapidly, will the SG-1 team succeed in finding a cure?

SG-1 goes to the planet Cimmeria in search of allies against the Goa'uld. Upon arrival, Jack and Teal'c are trapped in a labyrinth, where the only exit is through Thor's Hammer, a device to destroy Goa'uld, but preserve the host. Daniel Jackson must destroy the device that could someday have saved his wife in order to free his friends.

Daniel Jackson discovers that the Stargate was activated in 1945 and a young professor went through, never to return. Together with his still living fiancée, the SG1 team discover the now aged professor, naked and trapped in a decaying fortress, containing the secrets of an Ancient alliance. Will they be able to rescue him and escape to earth in time?

It is time for Teal'c's son Rya'c to have his Prim'ta. Can Teal'c stop his son from being implanted with a Goa'uld and becoming a slave to Apophis?

O'Neill, Carter and Teal'c return through the Stargate shell-shocked and distressed to announce that Daniel Jackson was killed. But Jackson was captured by the last survivor of an aquatic race, who planted false memories in the other members of SG1. Can the team remember and return to rescue Daniel?

The Goa'uld Hathor (one of the mothers of all Goa'uld), brainwashes the men of the SGC with pheromones, and nearly makes Jack a host to a larva conceived with Daniel. She flees after the unaffected women of Stargate Command retake the facility.

On an astronomical black hole observation mission, SG-1 finds a fatal bacterial mass-epidemic on a planet where the natives told then-incredulous Daniel months ago that the coming solar eclipse would bring disaster. They also take back to the Cheyenne Mountain Base a surviving, fairly healthy, orphaned young girl named Cassandra, and awakes Sam's maternal instinct. The Naquadah traces found in her blood turn out to have made her immune, but after she has a seizure they are diagnosed to constitute a huge bomb, somehow triggered by rescuing her; the whole thing must be planned as a 'Trojan Horse' by the Goa'uld. Sam takes the prospect of sacrificing Cassie personally and is prepared to take personal risks.

SG1 travel to a planet where Teal'c is recognised as once having been head Jaffa to Apophis. He is arrested for the murder of a villager and put on trial for his life. Then other Jaffa attack the village. Will SG1 be able to save Teal'c and prove that he has changed allegiance?

On their first visit to a new planet, SG-1 finds it subject to totally destructive volcanic activity and saves ten natives, the Tollan, a far more technologically advanced society. Their leader Omoc isn't grateful, nor interested in such a primitive race as the earthlings or any of the 'even more primitive' planets which are prepared to host them. Only one Tollan, Narim, shows an active interest in life on earth, especially in captain Samantha Carter and the cat Schrodinger she gives him, explaining his planet was destroyed after the Tollan supplied an unlimited energy source to a primitive neighboring planet which abused it for a cataclysmic weapon. Meanwhile, the White House authorized NID colonel Maybourne to take charge over the Tollan for military purposes, exactly Omoc's nightmare.

Following a Stargate technical defect, O'Neill and Carter are stranded next to a Stargate in a cave on an icy wasteland. O'Neill is severely wounded and both are freezing. Will the SGC find and rescue them in time?

After arriving on P3X-989, the team are rendered unconscious. When they wake, they return to Earth, but soon find out that they are androids. The team must return to the planet to find out what happened to their real bodies.

While collecting artifacts on a distant planet, Daniel Jackson is knocked out after touching a mirror-like object. He awakens in the same room but is unable to locate the other members of SG-1. Assuming that they left without him, he dials up his return home but gets there to find that he is in a different reality. In this world, General Jack O'Neill and Catherine Langford are in charge of the Stargate program; Hammond is a Colonel reporting to O'Neill; and Sam Carter is a civilian scientist working on the project (and also engaged to O'Neill). More importantly, Earth is under attack from the Goa'uld who have already killed over 1 billion people. Carter believes that somehow, Jackson is from a parallel dimension. When Jackson learns the point of origin of the Goa'uld attack, he wants to return to his own universe, believing that his Earth will be similarly attacked.

The Stargate team must justify the project's continuation when a doubtful senator, Head of the Congressional Military Appropriations Committee, comes to review the project's performance.

General Hammond has tried everything to get the Senate's decision to shut down his Stargate program undone, but the President personally refuses to 'commit political suicide': the Stargate will be buried. Daniel's insistence -that the danger for Earth as a whole outweighs everything- convinces his colleagues to ignore Hammond's command and dial the address that the Goa'uld invasion started from in the alternate reality that he visited. They arrive not on a planet but a new, superior type of starship, already launched by hyper-drive. A 'video' proves it belongs to Apophis, who gives command to his son Klorel, whose host is none other than the team's young Abydonian friend, Skaara. Overpowering Skaara seems their best move, while Sam installs explosives in the death glider deck with a 24-hour timer just in case, but the Jaffa manage to liberate Klorel. Jack discovers that the ship goes far faster than expected.

As the Goa'uld attack fleet approaches Earth, all four members of the SG-1 team are taken prisoner. They get help from an unexpected source when Bra'tac, Teal'c's mentor, reveals that he is on board. Apophis has delayed the attack until his son Klorel is revived, giving them some time to prepare. SG-1 has used all of the C4 on one of the two ships but must find a way to dispose of the second. Back at Stargate Command, Lt. Col. Bert Samuels arrives as a Pentagon liaison officer but also reveals a new weapon they have developed. General Hammond is dubious. They begin to transport humans to an Alpha site in order to ensure the continuation of mankind.

Samantha Carter becomes the host of a Goa'uld when she was trying to save the life of the previous host.

SG-1 inadvertently help a desperate criminal and are charged and sentenced as accessories to his crime. They are banished to a desolate, brutal penal colony and strike a deal with a powerful female prisoner to help them escape. But is this prisoner hiding something from them?

Exploring a strange and beautiful garden, SG-1 comes across a dome containing a race that are connected to machines. The team are captured by the machines and rendered unconscious, but awake to find themselves reliving pivotal moments of their lives, over and over again. Then they discover it is virtual reality and a mysterious keeper appears to persuade them to try different outcomes for the moments. But can the team escape his clutches, when they don't know what is real and what is not?

While walking through a forest on another planet, Jackson saves the life of a beautiful princess who is about to kill herself. SG1 is taken prisoner, but Daniel is freed by the ruler when he finds out that he saved his daughter. The rest of SG1 is sent to work in the mines for the rest of their lives. Jackson falls in love with the princess, but also becomes intoxicated by frequent use of a Sarcophagus. Will he come to his senses before the rest of SG1 are worked to death?

O'Neill and the team return to Cimmeria, the planet where they destroyed Thor's Hammer to help Teal'c escape. They find that the Goa'uld have invaded and many of the people are dead. Can they help to find Thor's weapons to fight off the invasion before they are all captured or killed?

SG-1 discovers an ancient artifact and brings it back to the SGC. Ariving at the SGC, it becomes active, pins O'Neill to the gate room wall, and unleashes a virus into him.

Teal'c's son Rya'c is kidnapped by Apophis and SG1 tries to rescue him. When Rya'c is recovered he denounces his father and helps to capture the team. They escape, but will they be able to return to Earth and cure Rya'c?

While O'Neill and Carter head to Washington to be decorated by the President and find a security leak, Jackson and Teal'c go to Abydos (after they unbury their stargate) to see Sha're's father. They arrive to tell him that they have been unsuccessful in finding Sha're, only to discover that she is already on Abydos. But they find that she is pregnant by Apophis and the baby holds the secrets of the Goa'uld.

While exploring a new planet, Teal'c is stung by a giant insect whose venom causes a terrifying transformation.

When Teal'c makes Sam Carter realize how valuable the knowledge left by Tok'ra Jolinar in her brain and the chance for an alliance can be, they convince General Hammond to let SG-1 attempt a meeting. They arrive on a planet which is deserted on the surface, but are awaited by well-camouflaged, armed Tok'ra who bring them to tunnels which they create by means of a mysterious crystal, which can also undo them afterward. Both parties are quite suspicious, the team feels like captives, and indeed, the Tok'ra leader Yosuuf fears they cannot be released, at least until the whole site is moved. Meanwhile, the Tau'ri barely overcome their suspicion against the Tok'ra Goa'uld biology (with symbiote), when asked to volunteer themselves as 'hosts', and Carter learns Martouf (and his symbiote, Lantash) was Jolinar's lover, hence has a special connection with her.

The attempt to forge an alliance with the Tok'ra seems a miserable failure, as SG-1 is practically imprisoned as a security risk and considered virtually hostile because 'blending', by agreeing to host a symbiote, is a bridge too far for each of them. When SG-3 arrives and informs Sam about her terminally ill father General Jacob Carter's quickly worsening condition, she realizes the symbiote's healing powers, confirmed to apply to cancer, make hosting an offer to good to refuse for him. Garshaw allows Sam and Jack to return and convince both generals to allow the plan, which is achieved. Meanwhile, the Tok'ra must hastily evacuate, destroying tunnels behind them, because a large-scale attack by Apophis's troops is expected soon, while Jacob meets his potential symbiotic partner Selmak and his equally terminal predecessor to help him decide. Jack verifies his strong suspicion there is traitor among the Tok'ra who is communicating with the Goa'uld.

SG-11 failed to report regularly while mining trinium, a vital mineral for earth's defense against the Goa'uld. SG-1 finds them missing, and all traces cease at the site of arrow-heads made from trinium. Then they are all sedated by such arrows and brought to the village of Tonané, whose earthly tribal ancestry Daniel identifies by its animal totems. However, they are soon awake and released, their guns even returned, and promised to get their friends back, too, from the wolf spirit T'akaya, and the raven-shaped supreme spirit Xe'ls. The council of elders refuses to allow resuming of the mining, which is disrespectful to nature, but Tonané is delegated to be shown alternatives on earth. Both teams return to SGC, or so it appears; in fact, SG-11 is a series of incarnated spirits, who are soon convinced the earthlings are most untrustworthy.

A climate control device is stolen from a planet and SG-1 is accused of the theft. They have to find it and restore it before the planet freezes. Then weather on Earth starts to unexpectedly change and the team believe that the device has been stolen by rogue NID agents. Will they find it in time and how did the NID travel off world?

SG-1 travels to a planet whose people are allies of the Asgard.

Stargate Command opens a wormhole to a planet with a black hole in orbit.

Daniel falls victim to an invention that swaps his body with that of a dying man.

Following on a Tok'ra tip, SG-1 goes to a planet where they find the hated Apophis, nearly dying and under attack by death-gliders. They get back with him, realizing he was tortured by a rival system-lord with lasting harm. Apophis demands sanctuary, provided Dr. Fraiser can save his life, at least on account of the human host, but without a sarcophagus the prognosis for his symbiont is lousy; he offers all his Goa'uld knowledge in exchange for a new host, i.e. his life, revealing he was defeated by the terrible Sokar, once supreme system lord till an alliance lead by Ra and Apophis unseated him. The confrontation with Daniel, on account of Amaunet/Sha're and their son Klorel, and with former prime Teal'c, is bitter for all three. The Tok'ra send Martouf to warn the Tau'ri must hand over Apophis, but their warning is ignored- until Sokar proves he can bombard the iris with accelerated particles and ultimately cut through it, so the White House orders his extradition, but before they can he dies, unlike his host, an Ancient Egyptian temple scribe of Amun.

While testing new technology, a UAV malfunctions and crashes on a planet. SG-1 goes to determine the cause of the malfunction, but discovers that their presence may be causing serious injury to the planet's primitive inhabitants.

When an incoming wormhole is established at the SGC, the iris is over-ridden and opened. A young boy appears and tells the SGC that they are in terrible danger from a group of terrorists. But these terrorists are invisible creatures and they are determined to wipe out all humans to prevent them being used as hosts to the Goa'uld.

A solar flare sends SG-1 back in time thirty years to 1969. Captured by military police at Cheyenne Mountain, they escape with the help of a young Hammond and then must find the Stargate so they can return to the present.

Colonel O'Neill awakens and is told by new staff everything in the SGC is different because he was just revived after 79 years of cryogenic hibernation, as sole survivor of a disastrous SG-1 mission on a Goa'uld-ruled planet. He accepts to undergo a 'high tech hypnosis' to retrieve information of use in the present war against them, which is going badly, involving earth's ten endangered colonies on other planets. However Major General Trofsky, the new base commander, and his female assistant tell Daniel and Sam, in different sections, that each of them is the sole survivor: it's all make-believe to probe their brains about the weaknesses of earth and the Alliance of the four races. Meanwhile, Teal'c awakes on earth, where it took Dr. Frasier months to save him from death; there was no trace of his teammates, and he resigns when General Hammond refuses permission to keep searching. O'Neill hears Goa'uld language, gets himself free and discovers he's on a fake SGC, frees Sam and Daniel, only to be stopped by the female Goa'uld system-lord Hathor, who employs both Horus and Serpent Jaffa and demands the humans' help against her rival system-lords.

O'Neill, Carter and Jackson are trapped on Hathor's planet. Teal'c and Hammond go to Chulak to forge a rescue plan and recover the team.

Sam's father hopes that SG-1 can help find and neutralize Seth, an Ancient Goa'uld who the Tok'Ra believe may still be hiding on Earth after thousands of years.

The Asgard and three Goa'uld System Lords meet at Stargate Command to negotiate a treaty modification, but subterfuge and treachery threaten not only the success of the negotiations, but Earth itself.

When the SG-1 team discover a sealed chamber of nine dead Goa'uld, Daniel Jackson is exposed to the parasites that killed them and threaten to drive him insane.

While employing the help of a planet's highly intelligent children for a project, the team discovers their horrific imposed fate when they reach a certain age.

Alternate reality versions of Kawalsky and Carter are caught at Area 51 after coming through the quantum mirror.

A bounty hunter, tracking down a Goa'uld, captures SG-1 and informs them that they too have a price on their heads.

SG-1 arrives on a planet where a culturally 'medieval Catholic' community lives in fear of an Unas they believe to be a demon, which regularly collects human sacrifices to Satan - in fact hosts for System Lord Sokar's army. When Simon implores SG-1 to spare his beloved Mary and take him instead, they even nurse her chicken pox. Simon hopes they are sent by God to deliver them from the satanic burden, but the canon who rules the village as 'spiritual' leader is faithful to Sokar and fears his authority, which rests on his right to select the 'damned soul' to be sacrificed, has been challenged, so he declares Teal'c a demon and incarcerates all SG-1. Witch-trial-type ordeals see the Jaffa 'proven' a demon and executed by drowning, and Daniel refuses the canon's warning to leave immediately. When Teal'c's symbiote allows a resurrection even Sam hadn't expected, they are all designated possessed and sacrificed, along with Mary. Simon follows the Unas with a staff weapon to liberate them, but he's not alone.

SG-1 come across another SG team being attacked by Jaffa. They offer to help but are shot by the SG team members. When they awake, they find out that the other SG team are Jaffa, loyal to Apophis, who are planning to infiltrate Earth. Can SG-1 convince them that Apophis is dead before the Jaffa fight to the death?

Responding to a help cry from Kasuf, SG-1 and more USAF wipe out a Goa'uld Jaffa guard to save most of the slaves on Abydonia. When Amaunet turns her hand device on Daniel, he can't bring himself to shoot his beloved wife Sha're, but Teal'c saves him by fatally staff-shooting her, and Abydononian funeral tradition squashes his hope of a sarcophagus resurrection. Crushed by grief, Daniel has apparitions of Sha're and, once released from hospital, resigns from SGC claiming the quest for his wife was his reason to join. Daniel's former research assistant, Dr. Robert Rothman, succeeds him in SG-1; but Jack is sure he'll be back. Sha're (or Amaunet's posthumous manual spell?) keeps appearing to Daniel life-like, telling him to forgive Teal'c and together find their boy who, as Harsisis, has all the Goa'uld knowledge in his genetic memory, which, to the Goa'uld, means he must be killed. Daniel agrees to return, but has a secret agenda, too.

The team discovers an early industrial world suffering from collective amnesia and has no elderly people.

Martouf leads a Tok'ra delegation with crushing news for Carter: her father Jacob/Selmak has been captured by Sokar and imprisoned on Netu, an Egyptian name for hell, on a moon of planet Delmal, where prisoners are sent to suffer eternal torture, and from where no one returns; only Jolinar has ever escaped. SG-1 mounts a rescue operation with Martouf, top-priority being any information Selmak can offer about Sokar's plan to subjugate the other system lords, an unprecedented threat for all humanoids in the galaxy. Teal'c must pilot a Goa'uld ship and keep it in orbit as landing is impossible except by small pod, but first Martouf taps into Jolinar's memory, which is partially blocked by some trauma beyond physical torture. Only when they're down and in the custody of Netu's lord Bynarr, does Sam realize he is the key, in a 'personal' way, but not voluntarily, as she had thought. Sokar learns of their presence from Bynarr and orders the team and craft destroyed, but this also means there must be a way out. Bynarr's prime, Na'onak, has, and is himself, a major surprise.

Now that Apophis has revealed himself, he promises the prisoners to overturn Sokar, which requires extracting an irresistibly valuable secret, to which end he drugs Sam with the truth serum 'blood of Sokar.' Apophis also implants a memory device in, and gives the drug to, Jack to torture him using the persona of his young son that died, and Daniel for the location of his Harsesis son. Martouf's love for Jolinar makes him betray that the Tok'ra are on planet Entac - a convincing lie, so Apophis's plan to earn Sokar's gratitude, and then kill him when rewarded with the lordship of Netu, is on a shaky basis. Teal'c must help the Tok'ra Aldwin prepare a nuclear weapon to explode the whole moon when his ship arrives as their last chance to eliminate Sokar, but he decides to rescue SG-1 instead, by flying in the path of the rings device on Sokar's ship when he arrives.

An alien incursion takes control of the base.

The SG-1 team is requested by the Tollan to participate in a trial concerning Skaara and whether he or the Goa'uld parasite, Klorel, has control of his body.

The SG1 team embark on a trip to visit a planet with an idyllic beach, but as soon as they step through the stargate, they find they are back in the SGC. They thought that they just left, but have been missing for hours. They soon discover that an alien device has been implanted in their brains and a being called Urgo reveals himself to the team. But no one else can see him and he is extremely irritating. Will they be able to extract him before they lose their minds?

After a cataclysmic meteorite bombardment, Col. Jack O'Neill finds himself stranded on a primitive planet with its Stargate apparently permanently inaccessible.

Col. O'Neill is dismissed from the SGC for stealing alien technology, and is subsequently approached to participate in an even more covert Stargate operation.

While redialing old Stargate addresses, the SGC discovers that a gate that was previously buried has become uncovered. They send a probe through and find two archaeologists. However, when they travel through the Stargate, they find that it is located in a society in civil war: one continent believes that the people were created by a Goa'uld, whilst their enemy believes that humans arrived from another planet - by the Stargate. O'Neill, Carter and Jackson are captured by the authorities and questioned, but Teal'c is wounded and blinded. Can he help SG-1 escape the hostiles and get back through the Stargate?

SG-1 believes they have finally found Kheb, a planet with a temple where they believe the child of Apophis and Sha're, a Harcesis with all the knowledge of the Goa'uld, is being held.

The SGC send a MALP to a huge pyramid and inside they discover a crystal skull like the one Jackson's grandfather found many years before. SG1 visit the planet and whilst Daniel is looking into the eyes of the skull, as his grandfather did, an energy field envelops him. Teal'c fires his Zat at the skull, but Daniel has disappeared. Carter collapses and the team minus Daniel return to the SGC. Teal'c returns to collect the crystal skull, but will he be able to find Daniel?

Ready to go on vacation, O'Neill is beamed away by the Asgard. Thor tells him that Earth is faced with an enemy even worse than the Goa'uld.

SG-1 has to deal with a Replicator infestation on a Russian sub on Earth while Major Carter advises the Asgard about combating the menace in their galaxy.

The SGC is contacted by an advanced and embattled alien human civilization seeking military assistance, but their exact reasons for it become increasingly suspect.

The SGC is visited by a Tok'ra named Anise who brings some armbands used by the soldiers of a long extinct race, which are supposed to increase the abilities of the wearers. O'Neill, Carter and Jackson put the armbands on and it increases their physical strength, but it also causes them to make rash decisions. Can they get the armbands off before they cause their deaths?

An old love of Teal'c approaches the SGC and the Tok'ra claiming that her Goa'uld symbiote has been convinced to defect with their help.

When an SG-team member tries to assassinate the Tok'ra leader, it is believed that some of the SGC have been converted into Za'tarc - programmed assassins. The Tok'ra Freya comes to the SGC with Martouf to try and test all SG-team members. But the Za'tarc detector suggests that O'Neill and Carter are actually Za'tarcs. Is this correct and is there another Za'tarc at the SGC?

Col. O'Neill and Teal'c realize they and their friends are trapped in a time loop.

The SGC learn that the Russians have a Stargate of their own and they need the Americans' help with their problems with it that are affecting them both.

While on an archaeological dig at the original Goa'uld home world, Daniel is captured by a young Unas. He tries to communicate with it and slowly builds a rapport. Meanwhile, SG-1 comes to the planet to find Daniel and they soon realise that some of the SG-team members there may have been taken over by Goa'uld. Will they be able to discover which ones in time to rescue Daniel?

On the Enkarans' new home, SG-1 discovers a giant spaceship is threatening the colonists as it terraforms the planet.

The SG-1 team awake to find they have lost their memories. They believe they are workers in an underground power station. They are told that they are helping to preserve life during an ice age. In truth, they are slave labor to a huge domed city above. When Teal'c starts to recover his memory and is given another amnesia treatment, he forgets his Kelno'reem and starts to die. Will the others recover their memories in time to save him?

The SGC is contacted by a strange man called Martin, a conspiricist who believes he is an alien. The question is, how does Martin know about the Stargate and how come he has a gate address and is he being drugged by others?

While testing a new spacefighter made from Goa'uld parts, Col. O'Neill and Teal'c are trapped when a hidden automatic recall function takes over and sends it into space.

When one of Daniel's professors dies in a lab explosion which might be related to the Goa'uld, he comes back to Chicago to investigate what really happened.

Teal'c is on his home planet, Chulak, where there is rebellion among the Jaffa warriors. He is betrayed as a sacrilegious shol'va (traitor) by Rak'nor, son of a Jaffa friend of his father, and handed to Terok, the torturer of system lord Heru'ur. Ignorant of his fate, the other SG-1 members join Jacob in a risky attempt to take hold of a space mine using a Tok'ra ship piloted by Jacob. En route to Apophis' spaceship, the expedition finds out that Teal'c is being offered as a confidence-building present from Heru'ur to cement an alliance with Apophis against the other system lords, which would make the Goa'uld threat more dangerous than ever. They decide to save Teal'c, but their attempt fails. However, Teal'c's resistance to torture and clear conviction that Goa'uld are not gods finally convinces Rak'nor, who now bravely acts.

General Hammond mysteriously retires from the SGC and a new general is brought in, who breaks up SG-1: Daniel and Sam are scientists, Teal'c is with SG-3 and O'Neill commands a new SG-1. O'Neill tries to convince Gen. Hammond to return, but he finds out that someone ordered Hammond to leave or they would hurt his grandchildren. While the others are occupying the new general, O'Neill tries to find out who that "someone" is. Thereto he must place his trust in the one person he hates most: Maybourne.

In 2010, Robert Kinsey is president of a brave new world since he concluded the alliance with the Aschen, a race discovered by SG-1 which lets humanity enjoy its far advanced science and technology, including a vaccine against aging. Sam is now a civilian scientist, married to ambassador Joe Faxon, whose only worry is failing to get pregnant. When she double-checks the Aschen doctor Mollem's computer with Dr. Fraser, who felt superfluous given superior medicine, they discover human fertility is down 90% worldwide in three years. Sam, Daniel and Teal'c turn to retired general Jack, who always warned against handing over technological control, for a daring plan to turn the clock back like general Hammond did once, sending a message to their past with the exact time of a solar flare, which Sam can calculate using the Aschen computer. Only one ingredient is out of their reach: the GDO device to control the Stargate's iris, which is in the White House. Sam implores her husband Joe to steal it, but he has a secret as well as sincere objections.

When a "chosen" boy found on planet Abydos is brought to SGC, he sends a telepathic message, causing Daniel Jackson's personality to undergo disturbing changes. Will the rest of SG-1 be able to solve the mystery of the boy's origin before he becomes a power-hungry warmonger?

SG-5's Lieutenant Barber commits suicide by jumping into the Stargate shortly after a mission on a planet where a palace abandoned by the Goa'uld about 200 years ago is being studied by Daniel. Soon after, Daniel develops violent mood swings and is committed to a hospital with a neurotransmitter brain condition, presumed fatal after all the other SG-5 members die. Meanwhile, SG-3 has visited the planet, finding only the light installation Daniel reported as particularly fascinating and a human teenage boy, Loran, who hid from Daniel's expedition, but now tells Jack he was left there by his parents, scientific researchers. Back in SGC, Jack also develops symptoms. Sam and Dr. Fraiser conclude that it must be some addiction linked to the light, so when Daniel is nearly terminal Jack, who might not have been exposed too long himself, must bring him back. Jack insists they try turning off the light, and leans on Loran, who is looking for a father-figure; he even gives Teal'c an early "birthday present," but has a dark secret.

Carter decides to inspire a brilliant but difficult Air Force cadet by introducing her to the SGC program.

When the SGC probes a new planet, an alien energy entity there responds by invading the SGC's computer systems, and then Major Carter herself.

On Juna, SG-1 gets a hostile welcome from the local warriors' leader Darian, who seems incredulous they even dared to return. They loyally deliver Sam and Teal'c to Cronus and told them to bury the Stargate. Cronus orders Darian to decapitate Daniel by staff weapon- to find his head is robotic. Cronus's obvious astonishment makes Darian doubt his divinity. At the SGC, Harlan urge them to go on a mission. The master robot-creator tells SG-1 that the robot versions of them he created need to recharge after 48 hours. In order to prevent the Goa'uld gaining access to their duplicates' memories, SG-1 reluctantly go to Juna. Darian now joins them, but feels most of his people won't dare challenge Cronus. The two Teal'cs concentrate on revenging the original's father by attacking Cronus recklessly, while the Sams and Jacks deal with the military problems and overthrowing the Goa'uld rule.

SG-1 delivers their newly confiscated Goa'uld mothership to help the Tok'ra evacuate their planet and deal with their disinformed Goa'uld spy in their midst.

Stranded in another galaxy while fleeing their attack on Apophis' fleet proves only the beginning of SG-1's problems as multiple enemies appear.

To help Teal'c's mind clear again, SG-1 asks Bra'tac to help. Bra'tac removes Teal'c's Goa'uld and Teal'c is forced to remember certain memories of his past in order to get back to the real Teal'c in the end. SG-1 is glad to have him back.

After being rendered unconscious during an expedition, Carter's subsequently-ordered furlough is interrupted by a mysterious being with a message and growing affection for her.

When SG-1 flees from an expedition with Col. O'Neill and some mysterious team member named Tyler, whom no one else knows about, stranded, the fitness of the team is questioned.

When SG-1 inadvertently dooms a planet upon arrival, the team must overcome Asgardian diplomacy and indigenous religious prejudice to put things right.

When Cassandra collapses at home, she is taken to the SGC for treatment. A retrovirus is causing her to emit an EM field and she expresses a need to return to her planet for an initiation ritual. SG-1 investigates and finds a Goa'uld laboratory, probably having belonged to Nirrti, meant for experimentation on the planet's population. They find that the ritual is part of the experiment, a time when Nirrti studies her subjects and cures them when she is done. SG-1 has found a way to cure Cassandra, but now all that remains to be found is Nirrti.

When Daniel's Unas friend, Chaka, is captured by another world's slavers, SG-1 goes to that world to rescue him.

SG-1 teams up with a Russian task force to investigate the disappearance of a Russian SG team on P2X-338. They discover that the Russian SG team released a creature that killed Marduk, a Goa'uld, in his sarcophagus. SG-1 must trust their Russian partners in order to escape the ziggurat alive.

With the death of Omoc, the subsequent sudden Tollan reconsideration of their tech embargo leads to SG-1 suspecting a government conspiracy.

SG-1 makes contact with the Aschen, unaware of that their homeworld is one they were warned previously from the future to be considered off-limits.

Carter gets kidnapped and taken to an abandoned hospital where two doctors work to study the remains of Jolinar. She finds out that they have a Goa'uld, taken from the Russians, which they are planning to put inside a man named Adrian Conrad to heal his sickness. They need Carter to tell them how to get the Goa'uld out after he's healed. O'Neill believes the government is involved with Carter's disappearance and contacts Maybourne. Together, with Daniel and Teal'c, they find Carter but also find out that the Goa'uld has escaped inside Conrad's body.

A strange ship is headed towards Earth, and the SGC suspects that Martin Lloyd and his companions may have something to do with it. O'Neill is sent to speak to Martin and is assigned as a military consultant on Martin's new show, "Wormhole X-Treme!", which uncannily resembles SG-1 despite Martin once again losing his memory. His former shipmates stall Carter and Daniel by throwing them off the trail and into the hands of the NID.

While SG-1 is conducting training exercises for new recruits, Jack gets a call about a "foothold" situation. Wounded by compromised officers, O'Neill must lead the recruits in retaking the SGC.

When Teal'c is trapped in the Stargate buffer, the team must juggle the technical challenges along with personal, interdepartmental and diplomatic rivalries to rescue him in time.

In a Tok'ra plan to wipe out the Goa'uld, Daniel goes undercover as Yu's servant to release a poison at a meeting of the system lords. Meanwhile a Goa'uld attack on the Tok'ra base leaves the rest of SG-1 with their hands full.

As the Goa'uld summit continues, Daniel finds himself face to face with Osiris. He fools him in the same fashion as he did with Yu, but cannot bring himself to cause the death of Sarah, Osiris's host. He remains to uncover information about the unknown master of Osiris. Lantash, having taken Lt. Elliot as a host, guides the rest of SG-1 in escaping the fallen Tok'ra base.

A large asteroid is discovered on a collision course with Earth.

A new leader has risen among the Free Jaffa, K'tano, former First Prime of Imhotep. SG-1, accompanied by Bra'tac, seeks an alliance between the Tau'ri and the large force he has amassed.

On an alien planet, SG-1 discovers an inactive android is the only survivor of the destruction of her civilization. They bring her back to the SGC for study and manage to reactivate her. Things take a turn for the worse when she "makes" a replicator bug for Daniel.

To fix a mistake caused by the fake SG team, the real SG-1 must enlist the help of two convicts. The threat of an approaching Goa'uld mothership stresses the repair of the Sentinel.

As Jackson suffers from a fatal dose of radiation, he struggles with the value of his life while his friends deal with the emotional and diplomatic repercussions.

While still dealing with the loss of Daniel Jackson the SGC is contacted by the Asgard who require assistance dealing with Anubis, who seems to have new shield technology that can repel Asgard weapons.

Master Bra'tac arrives with bad news: Teal'c's wife is deathly ill, and Teal'c leaves to be with her. Shortly thereafter, the gate is opened but nothing comes through. Then Carter discovers a very low power signal that is slowly building an overload powerful enough to destroy the Earth.

Anubis' weapon continues to threaten Earth. Various plans are tried until Jonas Quinn suggests something simple that just might work. Meanwhile, Master Bra'tac has discovered the planet from which Anubis is launching the attack. He, Teal'c and Rya'c journey there to put a stop to it.

When SGC detects an Goa'uld ship in orbit, SG-1 is dispatched with Jacob Carter to investigate. They find the ship to be abandoned with no discernible life signs and Sam determines it to be the same used to kidnap Thor. Once on board the Goa'uld vessel, they find that the crew had initiated a self destruct sequence. O'Neill would very much like to salvage the ship despite Jacob's warnings that it could be a Trojan horse. An examination of the computer core reveals that Thor may have been able to introduce a virus but Jacob was right: it's an ambush and the ship soon plunges in the ocean. SGC and the Navy mount a rescue operation.

The SG-1 team travels to the Antarctic science station when the scientists there discover an ancient body in the ice. The age of the ice core samples would indicate that the body predates mankind. As they thaw the body, it comes to life. It's a young woman who they call Ayiana. As Ayiana gains strength, those around her all fall ill having contracted an unknown virus which they believe Ayiana carried. The new arrival also shows healing powers and can seemingly cure any illness just by touch. As she does so however she weakens to the point of death. In the end, only Col. O'Neill remains untreated and SGC seeks the help of the Tok'ra who offer an unexpected solution.

After Sam receives an emergency call from geneticist Dr. Richard Flemming, the SGC learns that he has been working for Immunotech, a company owned by Adrian Conrad, who implanted himself with a Goa'uld symbiote in order to cure himself. Fleming has now gone missing and General Hammond orders Sam, Jonas and Teal'c to investigate. They head to Oregon where Fleming lived and worked and learn from the local Sheriff that Fleming isn't the first Immunotech worker to disappear. The locals are acting strangely and seem to suffer from memory lapses. What they eventually find is a town full of Goa'uld and NID seemingly aware of everything that is going on.

O'Neill's symbiont Kanan drags him to a planet ruled by the Goa'uld Ba'al, where Kanan was undercover. Ba'al captures and tortures O'Neil, whose only hope may lie with - Daniel Jackson?!?

Stargate Command is approached by representatives of Jonas Quinn's home planet seeking military hardware. Their world is divided into three territories and there is a long history of war among them. Jonas' country fears that the other two territories are about to sign a non-aggression pact thus making them vulnerable to attack. In return for arms, they are offering an abundance of Naquadria. SGC isn't about to get involved in what amounts to a civil war but there's another possible outcome when Jonas' one-time professor, Doctor Kieran, tells them of an underground movement ready to overthrow the government and seek out a lasting peace. SG-1 travels to Jonas Quinn's home planet to obtain information on the situation there but not all is as it seems.

SG-1 is providing security for three scientists who are conducting research on a far-off planet. Goa'uld warlord Khonsu arranges to capture the SG-1 team and O'Neill tells Jay Felger, nominally the group's leader, to use the gate and head back to SGC. Felger is quite enamored with SG-1, admiring their exploits and daring-do. Rather than follow O'Neill's orders, Felger and another scientist, Simon Coombs, transport themselves up to the Goa'uld ship. What the scientists don't know is that SG-1's capture is a ruse to allow Khonsu, who is actually a Tok'ra, to pass on information. O'Neill is quite annoyed with the two scientists but their presence proves useful in the end.

The Tok'ra are forced to evacuate their newly established base under attack from the Goa'uld. They flee to the SGC's Alpha site. Tensions rise between the allied factions, the Free Jaffa, Tau'ri, and Tok'ra. Jacob and Selmak feel the end of the Tok'ra is near and Sam finds a Naquadah generator has been sabotaged to function as a bomb. Jack suspects the recently arrived Tok'ra and attempts to weed out the traitor.

SG-1 makes first contact with the planet Pangar. It seems to be a peaceful world that have recently discovered ancient Goa'uld ruins. They offer Earth their greatest discovery, a drug called Tretonin, which they say keeps them entirely disease free. In return, they want the gate addresses for specific worlds, most of which turn out to be Goa'uld home worlds. An investigation further reveals that the wonder drug is based on Goa'uld symbiotes and the Pangarans reveal another secret - they have a symbiote queen, found in the ancient ruins. When a Pangaran guard is seriously injured, SG-1 asks the Tok'ra for help. They soon realize that the queen is the founder of their race.

A television news crew has unearthed information about an Air Force project called "Prometheus". They believe it to be a generator, but know it uses Trinium, an element not found on Earth. In order to keep them quiet the Air Force allows them to film the X-303, a spaceship based on Asgard technologies, otherwise known as Prometheus. Things turn south when the news crew arm themselves and hold the Prometheus, as well as Sam and Jonas, hostage.

Having regained control of the X-303, the SG-1 team finds itself in an unknown part of space. Rescue comes in the form of the Asgard, specifically Thor, who needs their help. The Asgard home world has been overrun by the Replicators and they require SG-1's help as well as the relatively low tech X-303. The Asgard had set a trap for the Replicators and hoped to use a time dilation device that would give them the time they need to find a way to defeat them. The problem is that the Replicators have turned off the device and the Asgard want SG-1 to go in and activate it. They accept the assignment but to meet their objective, O'Neill will face a moral dilemma.

SG-1 brings back an Ancient device, the purpose of which is unknown. When Jonas touched it the device activated. Upon reaching the SGC Jonas sees a large red insect fly into a wall, but no one else can confirm his sighting. The SGC is put into lockdown, but nothing is found. Jonas suspects that the Ancient device is causing his hallucinations, but to his dismay it is set to be shipped to Area 51. When Teal'c and Jack see the bugs as well, General Hammond decides to let Jonas take a crack at deciphering the Ancient text on the device.

Senator Kinsey is shot in the chest at a public event, killing him just before his party's presidential nomination. Jack is arrested for the murder, and General Hammond assigns the rest of SG-1 to uncover the truth.

Former Colonel Harry Maybourne comes to Jack with a proposition: Jack gets him a presidential pardon and Harry shows them the advanced weapons cache that Simmons was trying to get to. They go through with the deal, but Harry attempts to double cross SG-1. He manages to get through the portal leading to the cache, but with one unexpected item, Jack. They find themselves in a field and Harry's zat is missing. Jack, however, still has his P-90. Harry reveals that they are not at a weapons cache, but rather a utopia. He meant to live out the rest of his life there and believes that there is no way back.

The Russian SG team brings back a man who claims that his people are being experimented on by Nirrti. SG-1 investigate where the experiments are conducted, with the Russian SG team as backup. The inhabitants worship Nirrti as their god and savior from a terrible plague. SG-1 attempts to use the same device Nirrti used on the people to reverse the mutations, but the people turn on them at the arrival of Nirrti.

The US and Russia reveal Stargate Command and its operations to representatives of the other permanent members of the United Nations Security Council.

On a mission to observe a nebula, SG-1 finds a crashed ship and its three human survivors. They soon come under fire from an pair of aliens bearing the weapons of the survivors. They repel the attack, but one of the three is wounded. She is taken to the SGC for treatment while Sam attempts to repair the ship. Jack and Teal'c feel that there is more to the relationship between the aliens and these humans, and attempt to trap an alien.

Teal'c is having strange nightmares featuring Apophis in which he is human and a firefighter with the rest of his team alongside him.

On a shakedown cruise of the Prometheus, the ship's hyperdrive regulator becomes irreparably damaged. A nearby planet was listed on the cartouche of addresses found on Abydos and thus may have a stargate. After a short jump towards the planet, the Naquadria reactor overloads and must be jettisoned. After the reactor explodes above the planet causing damage, the fate of SG-1 and the crew of the Prometheus is in the hands of a once Goa'uld-controlled world that they're off to a rough start with.

On a routine mission, SG-1 encounters a civilization desperate to be freed from the clutches of a Goa'uld. While on the planet, Jonas falls ill and is suspended from active duty. His mysterious illness is diagnosed as a brain tumor but gives him the unbelievable ability to glimpse the future, a future where O'Neill and SG-1 are walking into a trap!

Riding in the elevator in the SGC, O'Neill is visited by Daniel Jackson who needs his help. Daniel tells him that Anubis is headed for Abydos to search for something called the Eye of Ra, a relic that would make Anubis all-powerful. It's essential that SG-1 go to Abydos and secure the Eye but no has seen it - including Daniel - nor has anyone ever been able to find it. On the planet they see their old friend Skaara and with Daniel's help locate the Eye. They also find a tablet that speaks of a lost city of the ancients. When Anubis and his troops land in force there is little anyone can do to stop them. In the end it's left to Daniel to decide if he will try to stop Anubis - thereby breaking a cardinal rule of the Ancients.

A group of nomads on an alien planet find Daniel Jackson naked in the middle of ruins and take him in. Jonas translates the tablet Daniel said was important and discovers that it describes the last city the Ancients were building before the plague. He surmises that the list of addresses Jack put into the computer while storing the Ancient data were Ancient outposts in temporal order. Thus the last of the addresses should be the "City of the Lost". SG-1 visits the planet and happens upon the nomadic people, now inhabiting the ruins of the Ancient city. There they find Daniel, but discover his memory is gone. They must recover his memories in order to discover the secret to defeating Anubis.

Anubis's super weapon has been put out of commission, but Yu's fleet has been diverted to the other side of the galaxy by Yu himself, allowing Anubis to escape into hyperspace. Jonas has been captured by Anubis and Daniel is still aboard Anubis's ship, evading capture. Anubis uses the mind probe on Jonas, learns of Naquadria, and begins his attack on Kelowna. The Kelownans seek aid from the SGC. Jack and Sam arrive on Langara to discover that the Kelownans have given Anubis Naquadria in order to secure their safety. They communicate with Daniel who is attempting to free Jonas. Teal'c has convinced Yu's first prime to seek a new leader of the System Lords, Ba'al.

A teenage boy shows up at the SGC claiming to be Jack O'Neill. He recalls a dream in which an Asgard was studying him. They determine that they must find this Asgard to fix what has been done to Jack.

In a firefight with Jaffa, Teal'c takes a staff blast to the gut. Without his symbiote, he cannot regenerate as he once did. Daniel feels that he cannot remember something important, so he goes searching through the logs for any sign of his lost knowledge. Teal'c expresses his feelings that the Tritonin has made him weak.

SG-1 investigate a seemingly idyllic and subtly advanced human colony sheltered inside an energy dome on an otherwise inhospitable planet.

While exploring a crashed alien ship full of passengers in cryostasis, an alien force has downloaded a number of their consciousnesses into Daniel.

When an SG geological exploration mission runs into deadly conflict with an indigenous Unas clan, Daniel gets Chaka to help seek an accord with it.

In exchange for new tech for the SGC, Warrick Finn asks for their help to win a dangerous spaceship competition.

To save his job, Dr. Felger tests a new virus on the Stargate Network to help control it and it ends up disabling it instead.

After being saved by a group of free female Jaffa, SG-1 is taken to the females' home world to meet their leader, Ishta. Ishta proposes an alliance between her all-female rebel group, Haktil, and the Tau'ri. The Tau'ri offer her Tretonin to supplant their practice of taking the symbiotes from defeated Jaffa in the service of the Goa'uld. However, since Tretonin has only had two test subjects, Teal'c and Bra'tac, they are cautious to spread it among their ranks.

Bra'tac and Teal'c encounter a heavily armed enemy with shielding protecting him from Goa'uld weaponry who took out two Goa'uld personal guards. They barely manage to defeat him and bring him back to SGC for study, but this new threat poses a greater problem for the Tau'ri.

The Tau'ri and Tok'ra have used their captured super-soldier to determine his planet of origin. With Daniel, Dr. Lee, and the Ancient device they found in the hands of Honduran kidnappers, SGC must find a way to retrieve them if they are to have any chance of defeating the newly encountered super-soldiers.

During an engine cool down break from hyperspace travel the crew of the Prometheus, with Major Carter as an advisor, encounter a space craft of unknown configuration. They hail the ship to no avail; the unknown craft opens fire upon the Prometheus. Carter attempts to override the safety protocols on the hyperdrive to make a short jump into a gas cloud, but in the attempt is knocked unconscious. She awakes to find the ship devoid of all its crew and, as she tries to escape the gas cloud by herself, she begins to hallucinate.

Jonas Quinn returns to the SGC to ask for assistance in saving his nation. He explains that the Naquadria was originally Naquadah and a Goa'uld named Thanos started a chain reaction to transform all of his planet's Naquadah into Naquadria. A large vein of Naquadah has just been affected and the Kelownan scientists believe that the transformation will cause this large a deposit to explode, taking their entire nation with it.

Maj. Carter has been set up with her brother Mark's friend, Pete Shanahan, a cop from Denver who thinks Carter works for the Air Force in a simple research capacity. Daniel Jackson is being visited in his dreams by his former lover, Sarah Gardner, who was possessed by the Goa'uld System Lord Osiris.

At the new Alpha site, Sam Carter and Selmak (the symbiote carried by Jacob Carter, her father) are working on a new weapon to defeat the Anubis superdrones when the planet is attacked by a fleet of Goa'uld ships. Carter escapes with the prototype weapon before the base auto-destruct is activated but finds herself being pursued by a superdrone.

The president has asked that a documentarian go to SGC to create a film about its operations. His arrival is unwelcome to most and he begins to clash with the base personnel. Nevertheless, he conducts his interviews with SG-1 and the scientists in the employ of SGC. Meanwhile, an off-world SG team finds the remains of an Ancient city.

The documentarian still a thorn in their side, SGC encounters an unforeseen predicament. With half of SG-13 off-world engaging enemy Jaffa, SG teams 1, 5, and 7 go in as backup. In the midst of heavy fire, O'Neill takes a staff blast to the chest. Many deaths from the encounter hit SGC hard and Senator Kinsey orders a full investigation into the matter.

Agent Barrett of the NID calls SG-1 to Los Angeles for a consult on a mass murdering of a rogue sleeper cell by a young woman. There they find many Goa'uld artifacts relating to Sekhmet, a subordinate of Ra. But how this operation is related to the Goa'uld eludes SG-1.

The newly inaugurated President of the United States is briefed by the Head of the Joint Chiefs of Staff on the Stargate program. Former Senator, now Vice President, Kinsey attempts to get his running mate to back his policies for the program, but the president decides to look into the situation himself. Kinsey gets Richard Woolsey to convince the president of his agenda.

Vice President Kinsey briefs Dr. Weir on the Stargate program before her meeting with the president. SG teams 1, 3, and 5 go off-world to attempt the extraction of a newly found Ancient repository device. Upon arriving at the location of the device, SG-1 comes under fire from Goa'uld ships. With no other way to disallow Anubis from claiming the knowledge for himself, Jack submits himself to the dangerous device.

With Jack having the knowledge of the Ancient repository once again in his mind, he and Daniel attempt to unearth the location of the Lost City of the Ancients. Bra'tac, bringing with him the news of an impending attack on the Tau'ri by Anubis, takes Teal'c to help him acquire ships and warriors for the defense of Earth. Dr. Weir attempts to cope with the overwhelming nature of her new job, while also dealing with the unrelenting ego of Vice President Kinsey.

In a last ditch effort, O'Neill activated an Ancient weapon in the Antarctic to defeat Anubis. With Jack still in stasis in the Ancient outpost buried in Antarctica, SG-1 tries to contact the Asgard. Meanwhile their new leader, Dr. Elizabeth Weir, tries to decide what to do about a request for peace talks from the Goa'uld System Lords.

The Asgard fleet has managed to destroy the Replicator ship, with Carter aboard, but cannot contain the debris. Talks break down with the System Lords, ending in a Ha'tak being dispatched to test Earth's new defensive capabilities. The Prometheus waits to engage the incoming enemy, but Thor arrives in the Daniel Jackson, with Teal'c aboard. They enlist the help of Daniel and Jack, still in stasis, to remove the threat of the replicators to the new Asgard homeworld.

General O'Neill is still in the early days of commanding the SGC and faces a major problem when newly arrived Russian Col. Alexi Vaselov collapses in his quarters. Dr. Brightman's belief that Vaselof may be contagious seems correct when Daniel, who was with the Russian when he collapsed, apparently goes mad and tries to leave the base through the gate. O'Neill locks down the SGC but the problem isn't contagion: the essence of Anubis is alive and well and seeking a new host.

As the new head of the SGC, General O'Neill is beginning to feel the weight of his load, and he starts to have second thoughts about the whole idea, questioning his own competency.

The discovery of the Stargate creates a war between two nations on the planet Tegalus with Daniel in the middle of it.

Dr. Lee is adapting a virtual reality chair for use as a training device. Teal'c thinks its current scenario is all too easy and agrees to work with them to make it more realistic. He enters the game scenario and is quickly "killed" at which point the chair shocks him. Lee says it must be part of its basic construct. As the scenario resets - it's an invasion of SGC by Goa'uld - Teal'c is repeatedly killed and shocked putting him in danger. The computer program is set up to learn after each scenario and the challenge for Teal'c increases at every turn. Daniel volunteers to enter the game as well to see if together they can find a way out.

Having obtained permission to live off the base, Teal'c rents an apartment, telling neighbors that he has recently arrived from Mozambique. He's under orders to keep a low profile but can't seem to help himself when it comes to helping his neighbors. He helps one who is about to be assaulted by three thugs, but it's his next-door neighbor who seems to need assistance. Krista is having problems with her boyfriend, Doug. Teal'c soon realizes that Doug is beating her and warns him that should he hurt her, Teal'c will kill him. It all becomes very difficult when Doug is found dead in Krista's apartment. Daniel Jackson soon after receives an offer - translate a Goa'uld text, and he will get ironclad evidence that Teal'c is innocent. Meanwhile, Carter is shocked when her boyfriend Pete Shanahan tells he asked for a transfer to the local police department and asks her to marry him.

Owner and CEO of Colson Industries declares in a press conference that there is alien life and that he has proof. SGC fails in its attempts to keep him quiet on the battle over the Antarctic. However, they are greatly surprised when the proof he shows the media are not his satellite images, but a living Asgard.

Teal'c is unhappy with his son's plans to marry. Ishta arrives bringing news that Hak'tyl may be compromised. Complications arise when O'Neill allows Hak'tyl to inhabit SGC until a new homeworld is found for them.

When the Stargate gets beamed out of SGC in the middle of the night, Teal'c is stranded off-world. Dr. Jackson and Colonel Carter attempt to recover the gate.

The replicator Carter and the real Carter work together with the disruptor signal. The replicator has a different plan.

General Hammond returns to SGC to take Dr. Jackson with him on a trip to Atlantis onboard the Prometheus. In the middle of their trip, the Prometheus picks up a distress signal and Hammond decides to investigate. Things get sticky when a Kull Warrior takes control of the Prometheus, leaving Hammond and his crew, minus Daniel Jackson, behind in a damaged Alkesh.

SG-1 is sent to warn Harry Maybourne that the goa'uld System Lord Ares is coming to the planet where he was banished, and in the process they find what may be an Ancient time machine.

Ex-Vice President Kinsey comes to Jack informing him of the Trust's activities including what seems to be a plan for the Russians to reclaim the Stargate they lent to the United States. He decides to use Kinsey as their inside man with the Trust. Kinsey wears a wire for his meeting with the Trust to set up a meeting with a high-ranking Russian general. The plan goes south when the signals get jammed just as the Trust makes an astounding revelation to Kinsey and they beam out.

A man breaks into Jack's house and hold him at gunpoint claiming that Jack ruined his life. Seven years ago he came upon an Ancient artifact at a garage sale that allows him to see all of SG-1's missions.

After a long absence, Jacob Carter returns to the SGC to tell Jack that the galaxy is under threat of takeover by the Replicators. The Goa'uld are under attack from the Replicators and are quickly being eliminated. Ba'al's armies are being destroyed and he arrives at SGC to suggest they work together to defeat their common enemy. Carter's doppelganger, RepliCarter, is leading the attack and she has kidnapped Daniel Jackson in the hope of learning of any weapons the Ancients may have created that could defeat them. Jackson gets help from an unexpected source - the Ancient, Oma Desala - or so he thinks.

Sam and Jacob are on the planet Dakara trying to configure the Ancient's device to destroy the Replicators once and for all, helped partly by Ba'al and Daniel, who succeeds in freezing the Replicators by manipulating Carter's duplicate.

Daniel finds himself in a strange time and place - a diner where Oma is working as a waitress. She gives him a clear choice - he can choose to die or to ascend but if it's the latter, he will not be able to help his friends fight Anubis, who has yet to be disposed of. He strikes up a conversation with another patron, Jim, who has his own take on the situation. Meanwhile, Sam decides the time has come for her fiancé to meet her father, Jacob. Jacob is not well, however, something he has kept from Sam for several weeks. After Pete surprises her - he thinks he's found the perfect house for them - Sam realizes she has to come to grips with her feelings for someone else. Teal'c and Master Bra'tac have information that Anubis may be gathering what remains of his forces for an attack on Dakara.

With the threats of both the Replicators and the Goa'uld greatly diminished and the sister ship to the Prometheus, the Daedalus, now under construction, SG-1 is anxious to get a ride on the new ship. However, the mood is somewhat darkened by a phone call informing Dr. Jackson of Catherine Langford's death. After the funeral, Catherine's niece gives Daniel "a few odds and ends" that her aunt wanted him to have. Upon delivery it is discovered that almost her entire collection was shipped to Daniel's lab. He finds in one of her books a possible location of a ZPM, but scans of the area showed that it was no longer there. Daniel proposes that they use the Ancient's time machine to take it from Ra at Giza in 3000 BC.

SG-1 has changed the course of history and made the SGC virtually non-existent. Doctors Carter and Jackson have helped Brigadier General Hammond to find the Antarctic Stargate, but are not being allowed to help any further. They help Jack to power up the time machine, and he gets Hammond to allow them on the mission to Chulak to find Teal'c.

With a new commander of the SGC comes a new leader of SG-1, Lt. Col. Cameron Mitchell, a former fighter pilot who flew an F-302 in the battle over Antarctica. However, he is deterred by the fact that all the other members of SG-1 are leaving for other ventures: Teal'c to manage the Jaffa Nation, Carter to Area 51 for alien R&D, and Dr. Jackson to Atlantis as an Ancient expert. Mitchell endeavors to keep the members of SG-1 for himself, but they are increasingly tough to convince.

Daniel and Vala have used the Ancient device to inhabit the bodies of people in the Alterans' home galaxy. They have been taken by a Prior of the Ori to meet the Doci, one who speaks with the Ori, their gods. Daniel surmises that the Ori are what the Alterans who became the Ancients left behind and have ascended in a similar fashion, but without the restrictions.

Martin Lloyd seeks out SG-1 for assistance when his failed TV show based on the real Stargate program becomes a feature film.

Daniel Jackson, who was left behind fighting off Adria while the other SG-1 members escaped through the Stargate, is found working as a Prior: the best in the business, who doesn't need to use any threats to talk people into conversion to Origin. Hoping there is still some of his personality left, the team (plus General Jack O'Neill) kidnaps him. Daniel explains how he temporarily has Merlin's personality and knowledge in himself, and had deliberately allowed Adria to turn him into a Prior, while delaying to finish Merlin's weapon she'd wanted, meanwhile hoping to get an Ori ship for Earth's side. But time is running out, since the team took unexpectedly long to capture him. Still, the generals, Carter, and Vala are most reluctant to go along with releasing him and opening the wormhole he needs to bring the weapon through. Even the White House wants to kill him, or at best, keep him in stasis until he is reverted to his human nature by Merlin's genetic manipulation. But then his plan is wasted- unless the others can be trained to do it in his place (so only they are at risk, not the entire galaxy in case Daniel is Adria's Trojan Horse). After giving them the necessary information, Daniel suddenly frees himself while Richard Woolsey is with him and takes control of a space ship after beaming up Jack too, just after the others have undertaken their mission to Adria's lair, where Daniel, about to be genetically reverted, arrives just in time to tip the balance in their favor.

As the new head of the SGC, General O'Neill is beginning to feel the weight of his load, and he starts to have second thoughts about the whole idea, questioning his own competency.

Col. O'Neill is dismissed from the SGC for stealing alien technology, and is subsequently approached to participate in an even more covert Stargate operation.

A man breaks into Jack's house and hold him at gunpoint claiming that Jack ruined his life. Seven years ago he came upon an Ancient artifact at a garage sale that allows him to see all of SG-1's missions.

Col. O'Neill and Teal'c realize they and their friends are trapped in a time loop.

SG-1 travels to a planet whose people are allies of the Asgard.

A teenage boy shows up at the SGC claiming to be Jack O'Neill. He recalls a dream in which an Asgard was studying him. They determine that they must find this Asgard to fix what has been done to Jack.

A strange ship is headed towards Earth, and the SGC suspects that Martin Lloyd and his companions may have something to do with it. O'Neill is sent to speak to Martin and is assigned as a military consultant on Martin's new show, "Wormhole X-Treme!", which uncannily resembles SG-1 despite Martin once again losing his memory. His former shipmates stall Carter and Daniel by throwing them off the trail and into the hands of the NID.

SG-1 is providing security for three scientists who are conducting research on a far-off planet. Goa'uld warlord Khonsu arranges to capture the SG-1 team and O'Neill tells Jay Felger, nominally the group's leader, to use the gate and head back to SGC. Felger is quite enamored with SG-1, admiring their exploits and daring-do. Rather than follow O'Neill's orders, Felger and another scientist, Simon Coombs, transport themselves up to the Goa'uld ship. What the scientists don't know is that SG-1's capture is a ruse to allow Khonsu, who is actually a Tok'ra, to pass on information. O'Neill is quite annoyed with the two scientists but their presence proves useful in the end.

Vice President Kinsey briefs Dr. Weir on the Stargate program before her meeting with the president. SG teams 1, 3, and 5 go off-world to attempt the extraction of a newly found Ancient repository device. Upon arriving at the location of the device, SG-1 comes under fire from Goa'uld ships. With no other way to disallow Anubis from claiming the knowledge for himself, Jack submits himself to the dangerous device.

With the Stargate program in danger of being terminated, the team is under pressure to find technology. Visiting a planet where they believe there is a creature that possesses the secret of invisibility, they encounter Apophis and his guards. Both sides receiving mortal wounds, they are aided by the planet's inhabitants, the Nox, a gentle people with a very large secret.