18 months have passed since the events of Day 4. With the exception of David Palmer, Tony Almeida, Michelle Dessler and Chloe O'Brian, the world believes that Jack Bauer is dead. Jack is living near L.A. under the name of Frank Flynn, working on an oil rig and living with Diane Huxley and her teenage son, Derek.
In L.A., David Palmer is visiting his brother Wayne, when he is killed by an assassin's bullet. As CTU scrambles to gather more information, an exploding car bomb kills Michelle and injures Tony. Chloe is also pursued by an unknown figure, but she eludes him and manages to contact Jack for help.
President Charles Logan and his wife Martha are visiting L.A. and are planning to sign an important arms treaty with the president of Russia. Martha seems to be unstable and is badly shaken by the news of Palmer's murder. Logan refuses to heed CTU's warnings of possible danger and call off the summit.
Jack is forced to take Derek along for the ride as he meets with Chloe and fights off a group of men who want him killed. He forces one of the men to confess that Jack has been deliberately framed for the murders of Palmer and Michelle.