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.

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.

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.

Jack and Chloe have a plan in place to eliminate the terrorist threat before any more attacks rock London. With no time to spare and lives on the line, Jack and Kate pursue crucial leads in an attempt to gain the upper hand on the incredibly intense circumstances. Meanwhile, key players reveal their true colors. intense circumstances. Meanwhile, key players reveal their true colors.

Jack Bauer and President Heller endure the unthinkable to thwart the terror attacks of mastermind Margot Al-Harazi. Meanwhile, CIA agent Jordan Reed faces a life-or-death struggle and Kate takes drastic measures to track down Margot before it's too late.

Jack and Kate race to save the life of a player tied to the terror threat; Jordan faces a perilous mission; President Heller engages Margot to put an end to her attacks.

As the smoke clears after the devastating events of the first five hours, tensions between President Heller and Prime Minister Davies boil over, and one of them decides to take matters into his own hands. In the meantime, Jack proposes a plan to locate Margot by using someone unexpected as his unsuspecting bait. Back at the CIA in London, Jordan raises suspicions about Kate's husband.

An unlikely duo joins forces to forestall an impending attack. The terrorist reveals her demands. The President orders a military lockdown, but it may be too late.