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.

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.