On Atlantis, Sheppard comes to visit McKay about his accompanying Keller on a good will medical mission to treat a village. Sheppard is curious why McKay is volunteering for the mission, on his day off, but lets it go. McKay goes to the departure chamber… to find that Ronon is going with them. McKay is less than thrilled. They arrive at the village and Keller explains the villagers have a mildly contagious disease and they should avoid physical contact. She treats a mother and child and suggests McKay and Ronon go get some lunch. At the nearby tavern, Ronon suggests that McKay doesn't need to be there but McKay sticks around. They go back to the house and discover Keller left for the tavern. They try to contact her on the radio but get no response. McKay heads back to the Stargate to get help while Ronon searches the village.
Keller wakes up to find herself bound and a man watching over her: Kiryk. He refuses to answer her questions and starts moving her off. Ronon finds Keller's tracks and those of a second man. The prints appear to have disappeared, but then he spots just the man's trails going into the woods: he's carrying Keller. Ronon insists on going after Keller and then finds a second set of tracks, concluding Keller is alive. McKay gets to the Stargate but it opens and he takes cover. A Wraith party comes through and spreads out to search the area. One of them spots McKay and chases after him. McKay notifies Ronon and starts shooting wildly behind him. He hides but it finds him and moves in to feed: Ronon arrives and shoots it down just in time, and identifies it as a Hunter on the trail of a Runner.
Kiryk says he's taking Keller someone without providing specifics, then leaves a false set of tracks. Keller hears footprints and sees a Wraith approaching. She warns Kiryk, who disappears, then comes up behind the Wraith and decapitates him.
McKay and Ronon go back to the village to evacuate and ask if there have been any newcomers like Ronon. Meanwhile, Keller asks about Kiryk's device and then asks for a rest break. He knows she's from Atlantis and she tries to make a break for it. He easily recaptures and stuns her.
Ronon and McKay get the villagers to the nearby caves and then Ronon insists on going after Keller. McKay has no choice but to follow along. Meanwhile, Kiryk explains to Keller that he's a Runner and doesn't believe that Ronon is no longer a Runner. She tries to negotiate with him but he doesn't believe her and they continue. Ronon follows the tracks but realizes Kiryk is up to something. They find Wraith blood and a single trail again, but Ronon realizes it's a trap set by the Runner.
Kiryk brings Keller to a cliff and teleports her upward, explaining he found a device that bonded to his skin and allows him to teleport for short distances. McKay lags behind and a Wraith comes up on him. McKay guns it down and takes its tracker. Meanwhile, Kiryk finally explains that he has someone he needs her to provide medical treatment while he leaves.
Ronon and McKay get to the cliff and find no way up so they have to go around. Keller offers to remove Kiryk's tracking device and he reluctantly accepts her offer. However, when she scans him she realizes he has a more complicated tracking device that has fused to his brain stem. There's no way to remove it without killing him.
Ronon and McKay avoid another booby trap while Kiryk gets Keller to a cave with a young girl inside. The girl, Celise, injured her leg in a fall and he waited until he could find an Atlantis team to provide medical assistance. He explains that Celise lived in a village where he stayed one night, and the Wraith tracked him there and culled the village. Keller determines that Celise's wound is necrotic and she'll have to operate, but warns she'll need stronger medication than she has. Kiryk insists that Keller can't let the girl die and then moves outside to stand watch. Celise clearly admires Kiryk and tells Keller he's not as mean as he acts.
Ronon and McKay are still on the trail and find a dead Wraith, impaled on one of Kiryk's booby traps. Keller repeats her warning to Kiryk that Celise needs further medical treatment on Atlantis and he'll have to trust her. He agrees but insists that Keller return Celise to him when she's healed. Keller warns that a life being hunted by the Wraith is nothing for a child. They're interrupted when Kiryk hears the Wraith Hunters approaching. He teleports in and kills one of them, then the other. However, a third one brings him down from hiding. Celise calls out and the Wraith goes into the cave and finds the girl. He moves in to feed… and Keller stabs him from behind, killing him.
Keller gets Celise and Kiryk clear of the cave and warns him that they need to get Celise help. He insists on carrying her to the Stargate but Keller warns it's too dangerous and suggest she use a defibrillator to short out the tracking device. Kiryk agrees despite the risk, since live or die he wins. She disables the device and McKay loses the signal on the Wraith tracking device. Kiryk's heart stops and she works to revive him. He comes to and they realize she also disabled the teleportation device. He gives it to Keller so McKay can examine it.
Ronon finds where Keller dragged her comrades to safety and follows the trail, and figure out Keller is working with her abductor. Wraith Darts pass overhead and they catch up to Keller, Kiryk, and Celise. Ronon attacks the Runner and Keller manages to break them up. Keller has to restitch Celise's wound while the Darts move in. Ronon and Kiryk agree to work together and Keller completes her work. A Wraith party launches an attack and they manage to hold them off, Keller holding her own thanks to some sparring lessons with Ronon. More Darts move in and the group heads for the Stargate. Keller gives McKay the teleport device while Ronon wonders what Kiryk's connection to Celise is. Ronon understands what the Runner is going through and assures him they'll get him out of the situation.
Arriving at the Gate, they find that the Wraith have secured the area. McKay gets the teleport device working and Kiryk rebonds it to his skin and goes on the attack despite McKay's warning it might not work. Kiryk takes out the Wraith soldiers and Ronon goes to help him. The device runs out of charge and Kiryk takes cover while dialing in the coordinates. He jumps through the wormhole and the Wraith all follow him in. It closes behind him and Keller gets Celise through the Stargate while McKay returns to notify the villagers they're safe.
Back at Atlantis, Celise recovers and Keller has determined that the villagers are willing to adopt Celise. Keller warns Celise that they haven't found Kiryk yet and Ronon gives the girl the doll that she dropped in the woods. Keller is impressed… and a disappointed McKay notices. Later, Ronon's is in the sparring room when McKay comes in and asks what Ronon's intentions are toward Keller. Ronon eventually admits he has some romantic feelings and McKay warns that he doesn't plan to step aside. They agree to let the best man win.