Osrtoff takes the CTU keycard before leaving Jenny's apartment where the bodies of Jenny and Dwayne lie. He reprograms the keycard so that his photo shows up on the CTU security system instead of McGill's image.
Buchanan and Audrey tell the President that they have no idea where the terrorists will strike next with the nerve gas. Their only lead is Henderson.
Kim Bauer arrives at CTU to meet Audrey. She is with a man named Barry Landes. Kim doesn't know that Jack is alive.
Audrey asks Jack whether she should tell Kim before he arrives to soften the blow. Henderson, who is in the backseat of Jack's car, says that Kim was depressed when Chase left her. Henderson and his wife Miriam were there for her when Jack wasn't.
Kim is unnerved being in CTU because this is where both of her parents died. Audrey tells her about Jack and explains that he kept her in the dark in order to protect her. Kim is speechless.
Novick is surprised when Vice President Hal Gardner turns up at the retreat because Logan asked for his help dealing with the nerve gas. Gardner doesn't agree with CTU's existing plan and he proposes a more sweeping one, much to the disdain of Novick. The Vice President wants to ignore the law by not obtaining Congressional approval for declaration of martial law in Los Angeles. He and Novick argue over casualty estimates. Novick tries appealing to Logan, but the President wants to follow Gardner's plan because it would make him appear in control of the situation.
As they enter CTU, Henderson tells Jack that he is only trying to protect the country."You don't want to know what I know," he says evasively. Guards take him into holding.
Ostroff is cleared for entry into CTU with his forged keycard.
Jack quizzes Audrey about Kim's reaction to his being alive.
Jack goes to Kim."I don't know what you expect me to say," she stoically greets him. Jack tries to explain why he didn't tell her the truth and Barry interjects. Kim asks Barry to give them some privacy. She tells Jack that she leaned on Barry when no one else was available. Jack says that it was more painful to leave Kim then to lose Teri. Kim doesn't know how to come to terms with his being back. He apologizes and begs her to stay because he has more to say to her.
Armed with a schematic of CTU, Ostroff finds an air duct.
Writhing in pain, Tony questions Buchanan about why Michelle was killed. Buchanan can't tell him anything because it is classified information and Tony no longer is an agent at CTU. Tony feels that, with all his years of service, he deserves to know. Buchanan admits that her death was part of a larger terrorist plot and that Henderson was involved. Tony warns Buchanan not to let Henderson cut a deal.
Audrey tells Jack that Barry is a clinical psychologist and that Kim might have been his patient. Henderson is clamped down in the interrogation room. Jack is confident Henderson will undergo extreme torture to keep his secrets secure.
Jack tells Henderson that the hyoscine-pentothal being injected into him is creating the pain. They will inflict him with more unless he tells them what they need to know. Henderson refuses. An agent named Burke gives him another dose, and Henderson winces immediately.
Novick catches up with Martha as she is having a cigarette. He encourages her to stand by her husband's side because he needs her. Novick was there when Logan prayed for her safety and anguished over the decision. Martha sees through his manipulation and asks Novick straight out what he wants her to do. He confesses that Gardner is advising the President to declare martial law. Novick needs her to counter that argument because her husband trusts her judgment. Martha says that Logan may not be as much of a pushover as they all believe him to be.
Ostroff hacks into the CTU mainframe and shuts down the air ventilation system. Techie Carrie Bendis sees an error in the environmental system and lets Edgar know. He brushes her concern off and says he doesn't have time to deal with it. Edgar tells her to check it out herself.
Martha finds Logan outside, alone in his thoughts. Although Martha is still angry with him, he is relieved when she puts her hand on his shoulder. She tells him that she has not stopped loving him."You have to get back to work," she says."The country needs you more than I do."
Carrie goes into the electrical room to see if anyone is doing tests on the air system. She sees the canister and immediately starts to warn someone with her cell. Ostroff stabs her in the neck before she connects the call.
Ostroff sets the canister inside the ventilation's fan and sets the timer to detonate in fifteen minutes.
Chloe tells Kim that, of the four people who knew Jack was alive, two are dead and Tony is in serious condition. The only reason Chloe is still alive is because Jack saved her. Chloe suggests that Kim try to cut Jack some slack.
Buchanan gives McGill the bad news that his sister and her boyfriend were found murdered. McGill is shocked. Buchanan asks whether they were involved in drugs or organized crime because the killings seemed like the work of a professional. McGill confesses that Jenny had stolen his CTU keycard.
Buchanan calls Chloe to see if security has been breached with McGill's keycard. She sees that it was used by someone less than an hour ago. Buchanan orders a lockdown of CTU.
Even with an increase in dosage Henderson still won't talk. His vital signs begin to crash and Agent Burke tells Jack that he needs to stabilize him. Suddenly, the building alarm sounds and Buchanan lets Jack know that someone stole a CTU access card. Jack tells Burke to stabilize Henderson.
Buchanan details Jack to a corridor to find the suspect, and Jack heads out. Edgar locates Ostroff on surveillance cameras and runs facial recognition. Buchanan notices that Carrie is not at her desk.
Edgar goes to look for Carrie. Meanwhile, Ostroff tries to make his way out of the building, taking a guard hostage. He kills the guard and takes his radio.
Jack comes upon the dead guard and sees that his walkie is gone. Jack radios that the suspect is in the stairwell, but sends a hand signal to an overhead surveillance camera that this is not true. Buchanan plays along. Ostroff overhears this communication and thinks he is in the clear.
Jack comes up behind Ostroff, who tries to shoot him. Jack kills him first and takes the timer with a relay switch. He also sees finds a PDA with a schematic of CTU's ventilation system. Jack suspects there may be nerve gas in the building. Buchanan immediately orders an evacuation. Edgar calls Chloe from the electrical room and she yells for him to get out of the building. Edgar sees Carrie's body but he doesn't notice the canister begin to emit gas towards the fan.
As Audrey runs out with Kim and Barry, they see workers in the other offices collapse. Chloe tries to lock down some doors to slow the rate that the gas will reach the rest of the building. Chloe manages to contain certain rooms, and the group heads to the situation room for safety. Jack orders Burke to take Henderson to the clinic isolation room and seal it off.
Chloe closes off all the safe rooms with biohazard strips. One of the techies is locked out, and Jack tells her to try to find another exit. They watch as the woman and the rest of the people outside fall down to their deaths.
Edgar comes running into the bullpen from the electrical room. He sees Chloe in the situation room and calls to her. She watches helplessly as Edgar falls to his death. Chloe's eyes tear up.