SG-1 finds themselves stranded in a crippled ship in a distant galaxy – with Apophis threatening to destroy them. Teal'c is brainwashed and made loyal to Apophis once again.
O'Neill and Lieutenant Tyler are ambushed by Goa'uld forces and trapped behind enemy lines – while the rest of their team discover they don't know who Tyler is.
When Major Carter is kidnapped by a terminally ill man who intends to use a Goa'uld symbiote to save his life, O'Neill is forced to team up with an old foe to find her.
An alien ship approaches Earth, sending SG-1 to an old friend for some answers – where they discover that Martin Lloyd has created a TV show about the Stargate program.
SG-1 trains a team of raw cadets, and Colonel O'Neill is forced to take them into a real-life battle situation when he learns of a possible alien incursion at the S.G.C.
Dr. Jackson's undercover mission to a Goa'uld summit is complicated by the arrival of a surprise guest. Meanwhile, the rest of the team is buried under the surface of the Tok'ra homeworld after a Goa'uld attack.
Earth finds itself threatened by something even larger than the Goa'uld when the team learns that an asteroid is on a collision course with the planet.