SG-1 discovers Daniel Jackson alive and living on an alien world, with no memory of who he is. The team hatches a plan to lure Anubis into a trap and destroy his new super-weapon.
The team returns to Jonas's homeworld when they learn that the Goa'uld are after its naquadria. When Jonas is captured by Anubis, Daniel is his only hope.
When Earth's attempts to exploit a newly-discovered naquadah mine are thwarted by a tribe of indigenous Unas, SG-1 must turn to an old friend for help.
While the S.G.C. investigates a seemingly unstoppable new enemy soldier engineered by Anubis, Daniel leads a team in search of an alien device in Central America.
O'Neill seeks help from a former comrade to rescue Daniel and Dr. Lee, who have been kidnapped in Central America. Carter, Teal'c, and Jacob infiltrate Anubis's super-soldier facility.
When the Kelownans discover that a massive underground vein of naquadah is being converted into naquadria, Jonas Quinn seeks help from Earth in avoiding the total destruction of his planet.
Daniel is plagued by dreams of his former girlfriend, who has been taken as a Goa'uld host. Samantha Carter begins a romantic relationship with a detective, from whom she must hide her life at Stargate Command.
Earth's secret off-world base is attacked by Anubis's forces, and Major Carter finds herself being hunted by the enemy. General Hammond and Jacob Carter make an unnerving discovery about the Earth-Tok'ra alliance.
A film crew arrives to document the work of the S.G.C. for eventual disclosure to the public, but finds that the base's personnel are less than eager to participate.
SG-1 is called into action while a film crew is documenting the Stargate program, but the S.G.C. comes under investigation after the mission goes terribly wrong.
O'Neill goes to great lengths to keep the Ancients' knowledge from falling into Goa'uld hands when the team discovers a second repository. Meanwhile, the President replaces General Hammond with a civilian diplomat.
Anubis begins a systematic assault on Earth, and the planet's only hope of salvation depends on whether SG-1 can find the Ancients' mythical Lost City.