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.

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

The team searches for a valuable Zero Point Module rumored to be hidden on the planet Dagan -- but their new allies have motives of their own.

With a brief opportunity to send a data transmission to Earth, members of the Atlantis expedition compose video messages home to their loved ones.

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.

While on personal leave on Earth, Sheppard and Ronon learn that scientists have engineered a human-form Replicator -- who is now on the loose.