Palmer, Mike and Lynne discuss various ways to dispose of the ticking bomb. They conclude that the desert is the best place to set it off. Jack determines that one man must pilot the plane carrying the bomb. He chooses to fly the plane himself and bids a tearful goodbye to his daughter. Tony and Michelle become suspicious of a Middle Eastern diplomat who is asking questions about the evidence against Syed Ali. Palmer departs for Los Angeles so he can be on hand when news of the nuclear bomb reaches the public.

The Russian and US Presidents are set to sign an anti-terror treaty when assassinations rock Los Angeles, a call from a distressed Chloe forces Jack into action and President Logan's wife believes there may be a conspiracy.

Jack takes Henderson to CTU for questioning. Once there, he faces an unhappy reunion with his daughter, Kim. Mike appeals to Martha for help as Logan faces pressure from his Vice-President to declare martial law on L.A. Lynn connects the theft of his keycard to an impending strike on CTU, but his warning comes too late to stop a terrorist from infiltrating the building.

Jack takes his fight directly to the President as he attempts to force a confession from him that will prove his involvement in the day's events. Martha vents her hatred for her husband in front of the press as Logan gives a eulogy over Palmer's body. Jack and Audrey share a tender moment when it seems the crisis has subsided, but Jack finds that his problems have only begun as his past catches up with him.

Jack and Sherry Palmer prepare for a dangerous meeting with the head of the war conspiracy at the L.A. Coliseum; David Palmer sits in as the Cabinet waits for confirmation of the Cypress Chip's invalidity; the air strike on the Middle East draws nearer; the conspiracy goes to an old agent to put Palmer out of play.

As the missile speeds toward its destination, Mandy cuts a deal with Jack and the President to give up Marwan's location in exchange for a full pardon on all of her crimes. Tony and Michelle share a happy reunion, but Jack finds his relationship with Audrey shattered as she makes her feelings known. Logan's advisor suggests a drastic course of action when the Chinese government demands that Jack be handed over to them for trial. Palmer tries desperately to warn Jack of the danger against him. Jack's life changes forever as Tony, Michelle and Chloe help him to evade the trap set for him by Secret Service.

To find the remaining suitcase bombs, both Jack and the President set up bluffs.

As the clock ticks toward the climactic series finale, three hours remain and a ruthless Jack Bauer is on an unwavering mission to uncover the truth, which only complicates circumstances for President Taylor as she prepares for a signing ceremony. Meanwhile, President Logan comes face-to-face with a formidable foe, and Chloe leads CTU on a high-stakes collision course with Jack Bauer.

Emotions run high as the harrowing day climaxes with resolute President Taylor closing in on a world-changing peace treaty and a vengeful Jack Bauer taking matters into his own hands for one last and unforgettable job.

With Tony in custody, Jack leads his interrogation, but is shocked when a code word Tony whispers in his ear leads to old friends and a plot much deeper than anyone in the FBI anticipated. Jack once again takes the law into his own hands when he breaks Tony out of the FBI's custody to deliver him back to the terrorist faction. Renee asks FBI technician Janis Gold to try to uncover a possible leak in the agency, but Janis is terrified when her discoveries point to fellow analyst Sean Hillinger. Colonel Dubaku sends a message to President Taylor, insisting that the US withdraw its forces from Sangala or risk a terrible attack on their soil.

The clock ticks toward the final seconds of Jack Bauer's most heroic day. As the world teeters on a terror plot of mass proportions, Jack and the team reunite one last time to avert an imminent international crisis. With little time left and the fate of the free world on the line, Jack is faced with an unthinkable and grave decision. Lives will be lost and the American administration will grapple with the day's most devastating news as the clock stops.

After Logan authorizes Palmer to take charge of the crisis, Palmer sanctions Jack and Curtis to infiltrate the Chinese Embassy on a covert operation to capture a suspect. Tony and Michelle continue to bump into each other's personal lives, while Buchanan expresses anger at being kept out of the mission. Jack faces Audrey's wrath when a medical dilemma places Paul's life in jeopardy.

Mandy uses Tony as leverage to try to force Michelle to aid in her escape. A Chinese security operative captures and interrogates one of the CTU agents involved in the raid on the embassy. Palmer and Logan argue over the option of evacuating all major cities that may be targets for the missile.

Jack and Lynn must take action when they discover that the nerve gas is breaking through the protective seals that are keeping the CTU survivors alive. Chloe wrestles with her grief over Edgar's death, while Tony contemplates revenge against Henderson. Martha bolster's Logan's spirit as he wavers under more political pressure from Gardner.

President Taylor undergoes a game-changing setback; President Hassan makes a decision that shocks his loved ones; trusted confidantes become enemies of the state.

Emotions run high as the harrowing day climaxes with resolute President Taylor closing in on a world-changing peace treaty and a vengeful Jack Bauer taking matters into his own hands for one last and unforgettable job.

Jack Bauer's harrowing day crescendos as he pursues final leads at all costs. The emotional toll of the day's events escalates when Kate Morgan learns the truth about her husband and Audrey confronts Boudreau about his duplicity. Making matters incredibly worse, the scope of the terror threat widens and the potential devastation reaches new heights.

Audrey pursues diplomatic channels to try to prevent a full-scale war. Meanwhile, Jack Bauer leads Kate Morgan and Mark Boudreau on a mission to locate their target before it's too late and the world is changed forever.

George pits Bob against Reza in hopes of learning which one is working with Second Wave. Sherry and Lynne clash over Palmer's speech to the press. Kate is interrogated by Syed Ali, who believes she knows too much about the bomb. Jack and Nina fight off a group of renegade soldiers while waiting to be rescued from the crash site. They nearly escape when Nina takes Jack hostage and demands to speak to the President.

Two traitors are uncovered. One is the mole in the Palmer administration who is working with Stanton. The other is the member of the Warner family who helped Syed Ali to bring the bomb into the country. Jack learns of Ali's location and tries to rescue Kate. Kim and Miguel hatch an escape plan to stay out of LA, but the results are disastrous.

Jack's efforts to break Ramon out of prison go awry when they are captured by a group of inmates during the riot. Chloe unwittingly stumbles on to Jack's drug problem and she is forced to reveal his secret to Kim and Michelle. Palmer begins his debate with Keeler, while Kyle prepares to sacrifice himself to save Linda.

Saunders begins making demands on the President. He forces Palmer to hold a strange press conference and then orders the death of the CTU agent who can trace him. Jack learns of a woman who can lead him to Saunders, but a surprise attack shifts the balance of power. As Gael's symptoms get worse, Michelle devises a way to relieve the suffering of the victims at the hotel.

Jack and Chloe infiltrate Wayne Palmer's penthouse where David Palmer was assassinated, in the hopes of finding a clue to his murder. Jack convinces Wayne to cooperate and finds some information in Palmer's memoirs that leads him to the airport where the Russian president is about to land. CTU and Secret Service attempt to capture Jack, but they only find Chloe as Jack and Derek slip through their grasp. Martha tries to convince her husband that she received an important phone call from Palmer the night before his death, but a tape of their conversation seems to contradict her claims. Jack goes to the airport to find a lead, but a group of renegade Russian terrorists take hostages, including Derek, before he can act.

Logan wrestles with his conscience when he learns that Martha is riding in the motorcade with the Suvarovs. Audrey convinces Curtis to take action as Lynn continues to abuse his authority. Jack learns that an ex CTU agent, Christopher Henderson, works for a company which is connected with the nerve gas.

Jack pushes Audrey for answers when evidence indicates that she may be involved with the terrorists. Wayne and Aaron flee from a group of gunmen who have orders from Henderson to kill them. Bierko and his men gain access to a natural gas plant, where they plan to distribute the nerve gas throughout L.A.