Fleeing from a surprise encounter with the Wraith, Major Sheppard falls victim to an alien symbiote which is feeding off his life force and slowly paralyzing him. While speeding back to Atlantis for medical aid, the team gets trapped halfway through the Stargate when the puddle jumper, damaged in the altercation with the Wraith, suffers a mechanical failure. With only thirty-eight minutes before the Stargate shuts down, Lieutenant Ford and Dr. McKay struggle to manually fix the problem. As the clock ticks away, the Atlantis team must come together, or perish in the harsh vacuum of space.