Teyla and Dr. Keller head for New Athos, where Teyla's people have taken up resident, and Dr. Keller is nervous that they thought so highly of her predecessor, Dr. Carson. They arrive on New Athos only to find the settlement empty, with indication they were attacked… or culled by the Wraith.
The two take cover as two primitives enter the camp, and Teyla leads Dr. Keller out of the village. She's identified the intruders as the "Bola Kai" and warns they're extremely dangerous. They head back for the gate but Dr. Keller falls down a ravine and twists her ankle. Teyla gets her to the gate but the Bola Kai are there and the Athosians' weapon cache is too far away. Teyla prepares to make a fight of it but the Bola Kai spot them and they flee into the woods. Dr. Keller isn't up for fighting but Teyla warns that the Bola Kai will hunt them down.
The two women head into the woods and find the weapon cache, but it's empty. They have to then cross rope bridge to get to a hunting blind to hide for the night, but Keller has vertigo. Teyla leaves her so the doctor has to cross over but almost slips. Teyla comes back to get her and they keep going, but Bola Kai warriors attack. Teyla manages to defeat two with improvised fighting sticks and the third runs off. Teyla chases him down and kills him, then returns in time to kill one of the survivors in front of the shocked Keller. They then find a bound prisoner but he's not an Athosian and Teyla prepares to abandon him. Keller insists on treating the man while Teyla goes to find the hunting blind. She then gets Keller and the wounded man there and while on watch, spots a burrowing creature. She kills it but Keller isn't thrilled at eating the raw meat.
The prisoner revives and explains he's Nabel Golan of the Genii, and was working as a spy. The Bola Kai, who worship the Wraith, summoned their masters who culled the settlement. Teyla isn't thrilled at the fact he was a spy but lets him live.
Keller spends the night hungry and Teyla isn't impressed with her willingness to rise to the challenge. The doctor reluctantly eats the food then discusses the fact that Teyla was coming to see an Athosian she was involved with. A Bola Kai spots them and they're forced to keep moving.
Ronon wonders about Teyla not checking in, and gets Sheppard and McKay to check in on her. Teyla is considering abandoning the wounded Golan when the Bola Kai attack and Teyla tries to fight them off. She's finally outnumbered and brought down, and taken prisoner with Keller while Golan slips away.
Sheppard tries and fails to raise Teyla on the radio, while Teyla warns Keller that the Bola Kai will torture them for information about Atlantis. They're taken before Omal, the Bola Kai leader, and he wants to know who they are. When Teyla accuses him of killing her people, Omal says that the village was already culled when they arrived and they're also hunted by the Wraith. Teyla is taken away and Keller gives them fake information about a gate address to buy them time and save Teyla.
Sheppard brings his team through the gate in a Puddle Jumper while Golan kills the remaining Bola Kai guards and frees them. Teyla thanks him and then he knocks her out and demands the Atlantis gate address from Keller.
Sheppard's team search the woods while Keller figures out that Golan is a Wraith worshipper and betrayed the Athosians, who are still alive. Keller manages to get the gun from Keller then shoots him in the knee. Teyla tries to get answers but the Bola Kai arrive, only to be gunned down by Sheppard and Ronon. Golan slips away and the team is forced to retreat back through the gate.
Later, Sheppard tells the recovering Teyla that Golan and the Bola Kai all disappeared, and they have no clue what happened to the Athosians. Teyla vows to make certain whoever is responsible will pay. Keller thanks Teyla for making sure she can see her remaining family again then says that Teller is suffering from something other then simply injuries…