After being called in by the President of the United States, former CTU Agent Jack Baur learns that terrorists are planning on detonating a nuclear bomb in the city within 24 hours. more
Jack rushes to reestablish his old undercover identity, but he is not welcomed back until he proves his loyalty with a shocking "gift." more
Jack's undercover work pays off when he joins a deadly mission. more
Jack turns the tables and finds a key to the nuclear threat, while CTU suffers a critical setback. more
While CTU scrambles to recover vital information, Jack comes face to face with Nina. more
Jack takes control of a prisoner and uses strong-arm tactics to try and get key information. Meanwhile, Sherry Palmer, now the ex-wife of President Palmer, makes her return; and Tony interrogates Reza... more
Jack flies with Nina to Visalia; Palmer's staff has a hard time accepting Sherry; Kim and Miguel start their drive to northern California; Mason orders Tony to bring Reza and Bob in for questioning. more
While Nina and Faheen are brought together, Jack and Michelle must try and decipher their conversation in Arabic for any clue to where the bomb is located. more
Nina looks for a deal from President Palmer to protect her from Jack. more
Nina tries to turn the tables on Jack before he can get revenge; President Palmer tries to assure the country that the terrorist threat is well under control. more
Jack takes Kate to a mosque to help identify a suspected terrorist; Palmer looks beyond the legal ramifications to possibly remove Roger Stanton from his NSA position; and Bob Warner turns violent while... more
Jack goes to extreme, life-threatening measures while questioning a suspect. Meanwhile, Palmer continues the interrogation of Roger Stanton no matter how uncomfortable the process. more
Jack and Kate discuss a situation in Marie's past. more
Jack finally comes across an object that might be a crucial discovery. more
Jack goes on a suicide mission to detonate the bomb in a safe desert location; Palmer plots crisis management strategy; Kim hitches a ride away from McCrae's cabin. more
Kim sees the mushroom cloud from the nuclear bomb in the far horizon and faces the certainty that her father is dead. more
Jack takes Kate to meet the man who claims the Cyprus audio tape is a fake. more
Jack must save Wallace from an attacking military force, so Wallace can provide evidence that will prevent an unnecessary war. more
With Jack still on the hunt for proof that the Cyprus recording is a fake, President Palmer is torn between reducing U.S. military casualties by committing to a surprise or calling off the attack completely.... more
Jack's life hangs in the balance as he's tortured by Kingsley's men. They want the computer chip that will prove the Cyprus recording is a fake. Meanwhile, Chappelle orders Tony to continue processing... more
When Jack finally takes possession of the computer chip, Tony and Michelle struggle to access the chip's audiofiles in time to prevent a war. more
Jack finds the man who forged the Cyprus Recording, but encounters resistance to bringing him in. Meanwhile, after Chappelle makes a major announcement at CTU, Tony puts his career on the line to help... more
Jack attempts to deliver the one person who can help to prevent the military attack now close at hand. more
As Jack and Sherry head to their final confrontation with Peter Kingsley, Novick receives new evidence about Kingsley and orders the CTU to aid Jack's efforts. more