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.

The team finds themselves in mortal danger when their Puddle Jumper ship becomes lodged in the Stargate.

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

When a massive storm threatens the city, Atlantis is evacuated -- only to be taken over by the team's newest enemy.

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

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.