A new Stargate team embarks on a dangerous mission to a distant galaxy, where they discover a mythical lost city -- and a deadly new enemy.

Sheppard tries to convince Weir to mount a rescue mission to free Colonel Sumner, Teyla, and the others captured by the Wraith.

After a series of run-ins with the Wraith, the team begins to suspect their Athosian allies of having a spy in their midst.

The team finds a world whose people are on the brink of a discovery that may make them immune to the Wraith feeding.

Major Sheppard plays a dangerous game of cat and mouse with soldiers who have seized control of Atlantis and have taken Weir and McKay hostage.

Nearly a third of Atlantis's residents are infected with a deadly virus that causes hallucinations and death, forcing a lockdown of the city.

A woman is found in suspended animation in Atlantis, and the team is shocked to see that it is Dr. Weir herself, who tells them of her trip 10,000 years into the city's past.

Plagued by terrifying nightmares, Teyla begins to recall a time when she and her father were captured by the Wraith and subjected to disturbing experiments.

With a group of Wraith hive ships on the way to Atlantis, the team searches for a place to flee and a way to destroy the city. McKay leads a team to try and activate the Ancients' orbital weapons platform.

All hope seems lost, until Colonel Everett arrives suddenly from Earth. He is determined to defend the city until the arrival of a ZPM, brought by a new ship.

A run-in with a Wraith Dart leaves the consciousness of a precocious Atlantis security officer trapped in Dr. McKay's mind.