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.

The Atlantis base is threatened when the team discovers that an alien entity is in the city. McKay's experiment with alien technology goes awry.

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

Efforts to open trade relations with a species called the Genii turn sour when the team discovers their new "allies" have ulterior motives.

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 finds a paradise world that would make an ideal sanctuary for those fleeing from the Wraith, but the local inhabitants believe their goddess will not permit it.

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.

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.