David Palmer tells Jack that he is being targeted by the Chinese.
Dale Spalding, a corrupt Secret Service agent, tells Bill Buchanan that he is under orders to arrest Jack Bauer. Spalding shoots at Jack, and Tony finds Jack unconscious and bleeding. Tony checks Jack's pulse and announces that Jack is dead. After Spalding and Buchanan leave, Tony injects Jack with epinephrine, which restarts his heart. Tony instructs Chloe to run interference with the coroner until Jack's body can be switched. According to Tony, Jack has to be "dead" in order to survive.
President Palmer speaks to Jack over the phone and acknowledges that the conversation is the final one the two will ever have. Jack thanks him for the warning and the opportunity to serve him for the past several years. Jack hangs up and steals away unnoticed as the sun rises...
Charles Logan pressures Bill Buchanan to find the person responsible before the Russian President arrives, but refuses to postpone the signing of the arms treaty.
Martha Logan tells Charles about a phone call she got last night from Palmer concerning national security which she thinks might be related to his assassination; Logan promises her to investigate it, but instead tells Walt Cummings that she's suffering from another delusion and he'll do nothing about it.
Jack Bauer, a.k.a. Frank Flynn, sits to have breakfast with Diane and Derek Huxley, during which Derek interrogates him; Despite this, Diane assures Jack she trusts him. He gets a call from Chloe O'Brian, following an attempt on her life, and he steals a helicopter and goes to Los Angeles to help her. After dispatching the hitmen, Jack questions their leader, Conrad Haas. After confessing he's the one that killed Palmer, Jack shoots him in cold-blood.
PresidentCharles Logan tells Walt Cummings about his wife's alleged conversation with David Palmer. Cummings then offers to investigate the call in order to try to bring her back to reality.
When Logan plays the recording to Martha, she insists that the phone call was indeed real, and that the conversation in the recording isn't.
Meanwhile, Cummings tells James Nathanson that he successfully fabricated and manipulated Martha's call with President Palmer.
As Jack sneaks out of Wayne Palmer's apartment, Chloe informs him that Chevensky is a baggage supervisor at Ontario Airport. At this point, Agent Jennings traps Chloe and Jack in the parking garage of the apartment building. Chloe drives the van out of the parking lot and gets captured. As she is being arrested, she tells Bill Buchanan that Jack's innocent.
Jack Bauer arrives at Ontario Airport and asks for Chevensky who commits suicide by ingesting a cyanide pill before Jack can stop him.
Outside, Derek Huxley notices armed men walking inside the airport and runs inside to warn Jack. As Anton Beresch and his men position themselves inside the airport, they set up an explosion outside and take control of the airport. As the crowd screams, Beresch tells the civilians inside the airport to be quiet and they won't be harmed, as long the President complies with their demands.
Logan and his staff watch the leader of the terrorists, Anton Beresch, make a live broadcast telling the public on TV that he will execute hostages unless the Presidents of the United States and Russia repudiate their accord. Logan pressures his staff to fix the hostage crisis.
Martha Logan wants to talk to her husband about her conversation with David Palmer, but Logan presents her with an innocuous recording (altered by Walt Cummings) where Palmer did not mention anything about national security.
To prove she was right, Martha gets a key card from Burke and finds out the transcripts of her conversation with Palmer in the archive room.
Bill Buchanan tries to negotiate with Beresch, but instead he executes a hostage in front of the camera and makes his point clear that he wants Logan and Suvarov to repudiate the treaty and that CTU shouldn't attempt a rescue mission.
Jack Bauer, while hidden inside the airport, feeds information to Curtis Manning and CTU. As he does so, he finds out from Diane that Derek is inside the terminal among the hostages.
Beresch learns that Jack Bauer is inside so he scrambles his cellphone signal and threatens to kill Derek if Jack doesn't come out. With Beresch pointing a gun at Derek's head, Jack comes out and surrenders.
Martha Logan talks to Evelyn about the proof she found of her conversation with David Palmer. Evelyn tries to convince her of telling the President, but Martha decides to hide the document in her blouse and wait. Later, Walt Cummings attacks Martha from behind, leaving her unconscious, and stealing the document.
At Counter Terrorist Unit, Lynn McGill and Bill Buchanan talk coordinate their efforts against the hostage crisis, while Curtis Manning finishes preparing the explosives for the raid. Lynn then asks Bill to take Jack into custody so he can debrief him.
Jack Bauer talks to Diane Huxley about her son, Derek, being in the middle of the hostage situation. After Jack surrenders, he tries to reassure Derek that it wasn't his fault and that things weren't over. After CTU successfully raids the airport, Jack informs Curtis about a hostage with a yellow tie who might be working with the terrorists. Jack offers to help, but Curtis tells him he has orders to take him to CTU. * Meanwhile, Ivan Erwich sneaks to a hangar behind the airport where he meets with a second team of terrorists. Erwich then uses the keycard Beresch gave him to unlock a container underground, revealing 20 bio-hazard canisters of Sentox nerve gas.
Ivan Erwich informs Schaeffer that the canisters were found where he had told them, and that they would eventually use it on Russian soil.
Walt Cummings is informed by James Nathanson that Erwich was successful in retrieving the nerve gas from the airport. They then agree that their only loose end left is Jack Bauer.
Cummings calls Spenser Wolff to ask for his help in dealing with Bauer.
After Logan's wife, Martha, is unknowingly attacked by Cummings, she tells her husband that she had evidence of her conversation with David Palmer, but now it has been stolen.
Cummings tries to convince Logan that Martha needs to be sent to a rehabilitation clinic in Vermont. However, Logan finds out that Martha escaped and asks Aaron Pierce to find her.
At Counter Terrorist Unit, Bill Buchanan interrogates Spenser after finding out about his involvement. Bill and Chloe realize Spenser had been tracking Jack since he arrived.
Jack Bauer kills Hank, an assassin sent to kill him. He then shows Spenser images of the assassin to find out who told him to let him into CTU. Spenser confesses that it was Walt Cummings.
Jack Bauer asks Wolff why he let in an assassin that tried to kill him, but Spenser tells him he was told the man would only tap the servers. When they ask him who gave him the orders, Spenser tells them it was Walt Cummings.
Jack tells Lynn McGill that Cummings is the connection to the terrorists, and that he's going to meet Mike Novick to recruit his help. However, Novick and Bauer are detained before they can talk.
PresidentCharles Logan chastises Walt Cummings for getting involved with terrorists. Walt justifies himself by telling him that their plan was to detonate the nerve gas at the terrorists home base, until Ivan Erwich found out about his plan.
Mike Novick considers to cover up Cummings' involvement to the media, but Martha thinks Logan should tell the truth.
Later, Novick calls Logan and tells him to come downstairs to see that Walt Cummings has apparently hung himself.
Lynn McGill talks to his drug-addicted sister, Jenny, who needs money. The two meet outside CTU, when Jenny's boyfriend hits Lynn from behind and steals his money and his CTU key card.
Ivan Erwich tells a mechanic named Cal that he and his team needs his help cutting into the canisters. Rossler gives Erwich specific instructions on how to cut them, on the phone. Rossler tells him they need to meet and Erwich agrees to call back in five minutes.
Jack Bauer and Curtis Manning raid Rossler's apartment and apprehend him. Erwich calls Rossler as Jack listens, and Erwich tells him he has the identification keys for the canisters. However, as they are about to move him, Rossler's female companion shoots him much to Jack's dismay. Curtis tells Jack that Rossler's was their only link to Erwich and he will call any minute.
PresidentCharles Logan is convinced by Lynn McGill to allow the terrorists to release nerve gas in a crowded shopping mall. However, Logan insists to Lynn that it better lead them to find the other canisters.
At CTU, Audrey Raines tries to talk Lynn out of releasing the gas, without success. Lynn argues that allowing the attack will eventually save more lives, as it might lead them to the other canisters.
Jack Bauer (posing as Jacob Rossler) hands the reprogrammed trigger to Polakov and Komar, but they decide to take Jack with them. When they are about to detonate the canisters, Bill Buchanan gives Jack the code, but Bauer tells Polakov the wrong code instead, despite Lynn's orders. Bauer tells Polakov there's nothing he can do, and Polakov knocks him out.
Ivan Erwich tells Polakov that they've found another way to release the gas. Some of it is released into the mall, but Jack is able to take out a terrorist. Polakov escapes and calls Erwich, who tells him to come back to him.
Curtis Manning and Bauer close in on the mechanic shop where Polakov has gone. Erwich spots them from afar and informs Polakov that he was followed. Polakov commits suicide as Bauer enters, realizing that they lost their only lead.
Jack Bauer talks with Audrey Raines who informs him that Omicron International made the Sentox for the military. At Jack's request, she confirms that Christopher Henderson works for Omicron, and he tells her Henderson worked for CTU and was the one who recruited him, before things ended badly between them.
When Jack confronts Henderson at his office, he takes him to a bunker in the company, where he shows Jack information on Omicron's Sentox program. However, Henderson deceivingly leaves Jack trapped in the bunker with a bomb. On his way out, he calls an associate to assure her that CTU doesn't have enough information to hurt them, and that Bauer will be dead in a minute.
Inside the bunker, Jack uses the bomb to blow the door open, while he hides under the floor.
As a result, Audrey convinces Curtis Manning to invoke Section 112 since she believes McGill is mentally unfit to run CTU. Curtis then has McGill placed in a holding cell.
President Charles Logan is informed by Mike Novick that his wife Martha is riding in the Suvarov's motorcade. Charles calls Martha and tries to convince her of getting out of the limousine, arguing that he has to allow the terrorists to attack the motorcade, or they'll release more nerve gas.
When the motorcade is attacked, Aaron Pierce calls for backup. Although several Secret Service agents are killed, Pierce manages to gun down the last attackers.
With Suvarov still alive, Vladimir Bierko calls President Logan and tells him that if Russia isn't going to pay with the life of its president, then its new ally, the United States, will pay with the lives of its citizens.
The Suvarovs and Martha Logan are attacked in their motorcade, but are saved by Aaron Pierce. President Charles Logan is frustrated that he gave in to the terrorists, but Mike Novick reminds him that they need to prepare for the terrorists to use the Sentox in America.
Martha Logan is angry that Charles didn't call back the motorcade. She shares a tender moment with Aaron Pierce before Mike Novick comes in and sees them.
Jack Bauer breaks into Christopher Henderson's home to interrogate him. When Henderson doesn't talk, Jack shoots his wife, Miriam, in the leg. Henderson still doesn't talk, so they prepare to bring him in to CTU.
While in holding, Lynn McGill tries to get his sister, Jenny, to give him back his key card. She wants to give it back, but her boyfriend, Dwayne Thompkins, claims to be getting $20,000 for it. However, Ostroff kills Jenny and Dwayne instead of paying them. He calls Vladimir Bierko and tells him that he's almost ready to access CTU.
Ostroff tells his superior Vladimir Bierko that he successfully reprogrammed Lynn's keycard; Bierko will launch the next phase of attacks after Ostroff's finished at CTU; Ostroff prepares the canister of nerve gas in front of CTU's ventilation fans.
Buchanan tells Tony Almeida that Michelle's death was part of a bigger plan to supply terrorists with Sentox nerve gas. Christopher Henderson is behind it all; Jack Bauer watches Rick Burke interrogate Henderson, who's hiding information.
CTU is compromised; a lock-down is in order.Jack Bauer finds that nerve gas is being deployed into CTU after killing Ostroff and seeing his PDA schematics of the building. Buchanan orders a Code Six evacuation. Audrey, Jack, Kim, Barry, Chloe, and several others witness Edgar's death.
Jack Bauer tells Lynn he's the only one who can reach the computer upstairs and release the oxygen to absorb the gas. After succeeding in doing this, Lynn dies from exposure to the nerve gas.
Tony Almeida has a gun in Medical and is about to kill Christopher Henderson when Jack convinces him they need Henderson to talk. After Henderson fails to talk, Tony takes over. Henderson suddenly wakes up from the coma and stabs Tony. Henderson escapes as Jack comes in and sees Tony on the ground. Jack holds Tony in his arms and cries.
At Counter Terrorist Unit Jack Bauer is forced to interrogate Audrey after she was named as a contact by Collette Stenger. After questioning Audrey and believing her to be innocent, Jack and Chloe found a link between Henderson and Stenger and realized that Audrey was being set up. Jack forces Stenger to reveal Bierko's target.
President Charles Logan tells Martha that David Palmer's assassin works for him. She accuses him of lying to her. Charles tells her to swear that she'll do as he asks for the good of the country. Martha tells him she hates him.
President Logan tells Graem that the situation with Martha has been taken care of. Graem warns Logan that his wife can't unravel everything they've worked for. Logan says that she won't.
Christopher Henderson calls President Logan and tells him that he has the recording, but that he has not destroyed it. Logan tells him that destroying the recording protects both of them.
Hayes calls Buchanan and warns him that Chloe was traced to his house and that they have seven minutes to get Chloe out. Buchanan asks Hayes why she's warning them, and Hayes replies that she may have made a mistake earlier. Chloe refuses to leave yet.
Jack Bauer rams Henderson off the road and corners him. Jack tells Henderson to give him the recording, but Henderson says he doesn't have it. Jack calls Chloe and says that Henderson no longer has the recording. Chloe says that he rendezvoused with another car, and Bill says that it went to Van Nuys airport, and whoever it was got directly onto a diplomatic flight. Jack sneaks on board.
Jack and a tactical team follow Bierko to the gas company to blow up the tank before the gas is released and apprehend Bierko. As the tanks explode, Jack catches Bierko and knocks him out. Jack carries Bierko out to the parking lot and instructs Curtis Manning to get Bierko back to CTU Los Angeles alive.
Jack Bauer hijacks Flight 520 and phones the pilot to tell him that the co-pilot, Scott Evans, has the recording. As the pilot gets up to unlock the cockpit, Evans knocks him out. Jack enters the cockpit and Evans hands over the recording. Jack calls Chloe and tells her that he has the recording.
Graem calls President Logan and tells him that Jack has the recording. He explains to President Logan that the plane must be shot down unless he wants to go to prison for treason and murder.
At Counter Terrorist Unit Karen tells Jack about a scheduled conference call with the Attorney General regarding the recording that incriminates President Logan. Jack gives the recording to Chloe O'Brian to clean up and prepare for playback. Jack visits Audrey in the medical clinic and tells her that he secured the recording and that President Logan will pay for President Palmer's assassination.
PresidentCharles Logan speaks with Graem and agrees that the country would not be able to handle a sitting President on trial for murder. President Logan loads a handgun and prepares to kill himself, but receives an unexpected phone call from Miles Papazian, who offers to intervene and destroy the recording. President Logan encourages Miles to act, so Miles distracts Chloe and points a laser at the recording.
CTU learns that Vladimir Bierko escaped custody. They learn that Bierko has another nerve gas canister that he plans to unleash. Buchanan and Karen plan to give Henderson a deal so he can help them track Bierko.
Jack Bauer offers Christopher Henderson a deal, and Jack agrees to help him to disappear, like Jack did, if he helps them find Bierko. They track him to a Russian submarine, the Natalia.
Vladimir Bierko plans to attack the U.S. using the Natalia's missiles. Jack Bauer and Christopher Henderson get on the ship, and Jack kills Bierko and his crew, which lets Henderson cancel the launch sequence and save the U.S.
Christopher Henderson corners Jack and makes him admit that he was never going to let Henderson go. Henderson fires at Jack, but his gun has no ammo. Jack reminds him that he was responsible for the deaths of David Palmer, Tony Almeida, and Michelle Dessler, and shoots him dead.
Mike Novick tells Martha Logan that she has to stall Charles long enough to let Jack get on the helicopter that Charles is taking to the airport. Martha seduces Charles into staying.
Mike Novick asks Jack Bauer what he plans on doing without the recording. Jack plans to get Logan to make a direct confession. Mike asks how far he will go if that doesn't work. Jack simply tells him, "As far as I have to..."