While Jack is questioned at the CTU, Teri and Kim are taken to the clinic to be examined. Meanwhile, certain he recognizes the name Jack Bauer, Palmer has Jack's background investigated. When he discovers that Jack was the sole survivor of a secret mission that he authorized two years ago, Palmer becomes convinced Jack is out for revenge and insists on talking to Jack face to face.

After Jack convinces Palmer he is not trying to kill him, they go over the "Operation Nightfall" file. The goal of the operation was killing a man named Victor Drazen, and a startling piece of information in the file convinces Jack and Palmer that they are both being targeted. Meanwhile, a scare at the clinic results in Teri and Kim being whisked away to a safe house.

Jack learns that one of the assassins, Alexis Mecir, is actually Victor Drazen's son and has become intimate with one of Palmer's aides. In an attempt to find the man ordering the assassinations, the aide agrees to plant a tracking device in Alexis' wallet. Back at the safe house, Teri and Kim discover their location is no longer secret or safe.

During their escape from the safe house Teri and Kim become separated, and the traumatic events of the day result in Teri passing out and then awakening with amnesia. Assuming her mother has been re-kidnapped, Kim conducts her own search for information concerning her mother's abductors. When the plan to track Alexis backfires, Jack pretends to be Alexis in order to keep a rendezvous with one of Alexis' contacts.

Against his family's wishes, Senator Palmer decides to go public about the secret scandal surrounding his family. Even as Alexis' brother, Andre, sends another assassin to the Bauer residence in hopes of finding Teri and Kim, a confused and scared Teri meets Dr. Parslow, a man who says they are good friends. Unaware of the danger Teri is in, he offers to give her a ride home.

As Kim tries to get the police to call CTU, Jack discovers that the empty field where the power grid is located actually houses a secret underground government prison and that night's scheduled arrival is none other than Victor Drazen, the man Jack supposedly killed two years ago. Now Jack's convinced Victor's sons are coming to break him out.

Jack's fears are proven true when Andre Drazen breaks into the underground facility to rescue his father. With Jack as his prisoner Victor calls CTU, but Mason tells him he doesn't negotiate with terrorists. Desperate to buy some time, Jack tells Victor that his son, Alexis, is still alive. Back at the police station the police finally let Kim go, but her drive to CTU doesn't go as planned.

Jack has Nina connect Victor Drazen to a hospital phone so he can talk directly to Alexis. Nina then advises Palmer of the situation. Palmer urges Mason to arrange the exchange Drazen proposed: the return of Jack for the return of Alexis. Although Alexis is delivered, Drazen holds onto Kim and tells Jack he needs to do one last thing if he wants to see his daughter again.

Jack arrives at Palmer's hotel with a phone on which Drazen will call and ask Palmer to unfreeze $200,000,000 of his assets. When Palmer tells Jack that Drazen knows that's impossible, Jack grabs the phone and throws it off the balcony. It explodes seconds later. Realizing Drazen will never give up, Jack suggests having the television report that Palmer died in the explosion, leaving Jack to offer himself up in exchange for Kim.

When Jack arrives at Drazen's location, he calls and asks to speak to Kim. Andre angrily refuses and says that they known Palmer is not really dead. Stunned, Jack hangs up and immediately calls Nina to tell her there's still a traitor inside CTU. Momentarily uncertain how to proceed, Jack is suddenly shocked into action when Nina calls back with tragic news.