With the Wraith armada closing in on Atlantis, Dr. McKay and a small team attempt to repair an ancient weapons satellite in the hopes of leveling the odds in the coming battle. Meanwhile, tension builds between Teyla and some of the other members of the Atlantis team over her connection to the Wraith. Major Sheppard steps in to defend her, but even he begins to harbour doubts when a team member is left unconscious after an attack by an unknown assailant.