Kolya (Cowen's Genii Commando that previously attempted to seize Atlantis) captures Sheppard using a transmission code stolen from the new Genii leader, Ladon. Kolya believes that Ladon stole his rightful place as leader of the Genii. It was Kolya who planned the Cowen coup. Ladon exposed Kolya to Cowen which forced him to flee.
Sheppard finds himself in a cell next to a Wraith.
Kolya establishes a video hook-up with Atlantis and demands that Weir turns Ladon over to him. When Weir refuses, Kolya turns the Wraith on Sheppard to feed on him, making the team watch, helpless to stop him. Kolya pulls the Wraith off, allowing Sheppard to live for three hours until Weir turns Ladon over. This goes on and on. Each time Sheppard is fed upon, his chances of survival diminish.
When Sheppard is near death, the Wraith stops himself from feeding. The Wraith admits Sheppard is the strongest human he has ever fed upon. When Sheppard asks the Wraith why he stopped, the Wraith says "The longer I feed, the weaker you become. And we will need what strength you have left...to escape." Meanwhile, back at Atlantis Weir lets Ladon go home in order to interrogate the men he suspects of leaking the stolen transmission code to Kolya. Weir's team is unsure whether she's making a mistake in letting Ladon go.
Sheppard and the Wraith bust out of prison together. The Wraith knows the lay of the compound and guides Sheppard out. The Wraith gets shot up in the escape and needs to feed to recover his strength. The Wraith and Sheppard agree they need each other and will continue working together until they can get to the Stargate and go their separate ways.
Sheppard and the Wraith don't know where the gate is, but they know it's heavily guarded by Kolya's men. The Wraith tells Sheppard if he doesn't feed soon, he'll die. Sheppard tells him to "buck up". He reminds the Wraith of their deal that they'll both go home alive. The Wraith asks Sheppard what will happen if they should meet in the future. Sheppard replies "all bets are off". Sheppard tells the Wraith to get some sleep while he takes the first watch. Sheppard holds out hope that his team will find him before the Genii do.
Meanwhile, Ladon discovers the location of Kolya's base and gives Weir the dialing coordinates. She sends Ronon out with a cloaked Jumper and a team of Marines.
It's morning. The Wraith awakens to hear Kolya's team approach. Sheppard (being an old man now after so many feedings) has fallen asleep. The Wraith feeds on him again. Having received strength from his latest feeding, the Wraith easily defeats Kolya's men, taking time to feed on two men at once. The Jumper makes it through the Stargate and begins their search for Sheppard.
Meanwhile the Wraith hovers over Sheppard, who looks to be about 100 years old. Sheppard tells the Wraith to "finish it". The Wraith says: "As I told you John Sheppard, there are many things about Wraith that you do not know." The Wraith proceeds to place his hand on Sheppard's chest.
Ronon and the team, now on the ground, hear Sheppard screaming and rush to his aid to find the Wraith over Sheppard. Ronon is about to shoot the Wraith, when YOUNG Sheppard jumps up and orders Ronon to leave the Wraith alone.
The team is perplexed as to why Sheppard has regained his youth. They ask how this is possible. The Wraith says: "The gift of life is reserved only for our most devout worshipers and our brothers. Sheppard gave me back my life. I merely repaid the debt."
Kolya escapes. Sheppard stuns the Wraith and drops him off at a Wraith-occupied planet. When the Wraith wakes to find Sheppard standing over him, he says: "Ah Sheppard...I thought you..." Sheppard says: "There's a lot you don't know about humans."
Wraith: "Next time we meet..."
Sheppard: "All bets are off!"