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?

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.

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?

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.

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

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.

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?

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 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?

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.

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 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.

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

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.

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.

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.

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.