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.

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.

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.

Following the death of a Jaffa on Earth and the disappearance of a prominent businessman, SG-1 starts an investigation into what remains of the Trust and into the actions of the Jaffa Nation. They discover that Ba'al is hiding on Earth after losing his forces to the Jaffa and that the Jaffa are secretly attempting his capture.

The SGC is approached by an Al'kesh bomber which lets itself be taken down, so they can capture Ba'al, who offers to exchange the necessary information to find Merlin's weapon for human help to eliminate his clones, which want to kill him. They mistrust his story, as does NID Agent Malcolm Barrett, who, however, fails to take over the investigation. Since the captive might actually be a clone, several missions to different planets retrieve and capture all clones, but which is the real Ba'al, and what are his true intentions?

Vala gambles, wins a cargo ship, but is found cheating; then Adria appears, throws everyone out and claims she has a new Ori fleet and an operational intergalactic Stargate. Vala tells her scary daughter how she helped Daniel, after a dream, reading the mysterious clava thessara-symbol's mystery, which led to a single planet address, where Athena's treasure house must be; after a disastrous visit there, the team refused to follow the next interpretation, fearing it's just a trap set up by Adria, so Vala is declared a security risk, grounded and confined to Area 51, but escapes through the Stargate. Adria takes her along as she hears the team still plans to visit the address, by starship. Upon arrival, they are trapped by SG-1, which however finds itself surrounded by lord Ba'al's troops. Ba'al uses the rings to beam up Adria into an electromagnetic cage in his starship. Back on Earth, General Landry worries what damage the two might do together and wants Adria back. Daniel and Sam now show Vala she has been implanted by Galaran technology with fake recollections of her entire adventure 'til the meeting with Adria. Even though she claims that's impossible, Ba'al is confident he can take control over Adria's loyal Ori troops through her- by implanting a symbiote. The team finds Ba'al's Jaffa and clones killed by symbiote poison, except one Jaffa who secretly used tretonin. The team ring-beams from the cloaked Odyssey starship into Ba'al's, shoots him and captures Adria, but back on Earth, she is found to be under the control of his symbiote. Instead of just killing the evil double, they contact the Tok'ra which send Ta'Seem to extract the symbiote and replace it with a Tok'ra one, but Ba'al manages to poison Adria, who has to be put down. Suddenly Adria wakes up, uses mind-power barricading herself in the sick bay with Vala, tells them she needs time to prepare for ascension, as Daniel guesses outside, and succeeds before the team can cut their way in by blow torch. Nobody knows what this will mean for the future, especially as it remains uncertain whether the Ori are still alive. If not, she may have gained all their former powers, and at least one clone of Ba'al still remains...