During a routine science mission on planet P3M-736, Maj. Lorne's team discovers a Wraith that has been shot to death. When Dr. Beckett determines that the carcass is missing an enzyme sac from its right arm, Sheppard and Weir immediately presume that Ford might be the killer, because he was addicted to the enzyme when he escaped from Atlantis.
Hoping to find their missing teammate, Sheppard, McKay, Teyla and Lorne return to the planet, split up, and begin a search. Sheppard and Teyla soon locate the trail of someone they hope is Ford, but when they give chase they are shot with a stun gun.
They awaken in a cave, prisoners of the mysterious warrior Ronon Dex. Years ago, Ronon was captured by the Wraith, implanted with a tracking device, and released. Ever since then, the Wraith have been hunting him - whether for sport or some other purpose, he doesn't know. He has survived by living an isolated, paranoid, and violent life, and he isn't about to start trusting two strangers just because they claim to be good guys. He does, however, tell his prisoners that, recently, when a Wraith hunter cornered him on this planet, a man fitting Ford's description appeared and brutally gunned down the Wraith, saving his life.
Meanwhile, realizing that Sheppard and Teyla are missing, McKay and Lorne expand their search. When Lorne is shot with a Wraith stunner, McKay's horror only grows as Ford steps out of hiding, revealing himself to be the shooter. Displaying a strange mixture of his old personality and a new, crazed obsessiveness, Ford insists that he now has "valuable powers" and wants to help rescue Teyla and Sheppard. His strategy to win McKay's trust, however, involves dragging the scientist on a meandering trek through the planet's forests while issuing occasional, semi-coherent death threats â�¦ so McKay is inclined to remain skeptical of his claims.
To escape this planet, Sheppard and Teyla will have to win the trust of a man who has forgotten what that word means, and McKay will have to match reason against drug addiction. And, in the end, they will all have to face the fact that - no matter what they do - their friend Ford might be lost to them forever.