SG-1 is accused of stealing an important weather-controlling device, sending a primative planet into chaos. The team discovers that Earth's second Stargate is being misused.

While searching for the Lost City of the Ancients on a distant planet, SG-1 is stunned to find Daniel Jackson alive and in human form but stripped of his memory. O'Neill convinces Daniel to return with them to the SGC, where he is reinstated for a daring mission to destroy Anubis' powerful new super-weapon!

The team investigates an unstoppable new enemy soldier engineered by Anubis. Dr. Jackson leads a team in search of an alien device in Central America, but gets more than he bargained for.

Earth's secret offworld base is attacked by Anubis' 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.

O'Neill goes to great lengths to keep the Ancients' knowledge from falling into Goa'uld hands when the team discovers a second repository. The President replaces General Hammond with a civilian diplomat.

General O'Neill tries to settle into his new job, but faces never-ending crises - including the capture of SG-1 by the Goa'uld.

After the Prometheus responds to a distress call from a Goa'uld ship, Daniel Jackson finds himself a captive when Earth's ship is stolen.

The fate of the galaxy hangs in the balance as Sam and Jacob search for the only weapon capable of stopping the Replicator onslaught. O'Neill leads a defense of the S.G.C., while Daniel squares off against Replicator Carter.

Baal kidnaps Teal'c as part of a plot to brainwash those Jaffa advocating a move toward democracy. Cameron Mitchell learns that an old friend is about to die.

SG-1 is captured after a deal with the Lucian Alliance goes bad ... and the planet's Stargate goes missing. Meanwhile, a former System Lord attempts to rebuild his empire.

Mitchell and Carter are shifted to another dimension, making them invisible to everyone at the S.G.C. Meanwhile, Teal'c and SG-9 discover that the Sodan have been brutally attacked.

Teal'c discovers a world where people are being savagely attacked by an elusive creature, leading SG-1 to a stunning discovery about its potential origin.

SG-1 tries to defend a planet from the Ori by hiding its people in another dimension. Vala attempts to convince her husband Tomin of the Ori's true motives.

When a terrorist attack decimates a Jaffa summit Teal'c strikes out on a quest for revenge, believing that the perpetrator is one of his own pupils.

SG-1 hatches an elaborate plan to try and capture Adria, using Vala as bait.