Nina and Tony realize that Jamey is working for Gaines, and lock her up in the Internal Technical Support room. Using instructions and equipment from Gaines, Jack gets in to see David Palmer's appearance at the San Clarita power plant, but is taken into custody by the Secret Service. Gaines executes Plan B.
Jack uses Sherry to lure Peter Kingsley out into the open, where he reveals the recording is false. Palmer's attorney convinces Mike Novick to release Palmer from custody. Palmer and his cabinet gather to watch as Sherry meets with Kingsley. Mike orders Ryan Chappelle to reinstate Tony and Michelle. Jack sends Sherry in for the meeting with Kingsley, and he is killed. An assassination attempt is made on Palmer's life by Mandy.
Kim goes undercover in a mission that may help CTU gain a bargaining tool for Stephen Saunders. Chase finds the man who left the hotel. CTU learns that the virus has begun to spread to the general public. Saunders makes another demand.
A train is bombed in Santa Clarita, killing dozens of civilians. While at CTU for a budget meeting, ex-agent Jack Bauer becomes involved in the attempt to stop the terrorist group responsible for the bombing after learning that their next target is his new boss, Secretary of DefenseJames Heller and his new girlfriend, Audrey Raines.
Eighteen months after faking his death, Jack Bauer, who's assumed the name Frank Flynn, returns to Los Angeles after the four people who know he's alive come under attack. President Charles Logan prepares to sign an important arms treaty with the President of Russia. First LadyMartha Logan is disturbed about the morning's events. Jack learns that he's being framed for the attacks.
Jack finds out that Abu Fayed, not Assad, is behind the attacks, and manages to escape. Jack teams up with Assad to stop a suicide bomber on a subway. FBI agents search the Islamic-American Alliance offices in D.C. under dubious pretenses, to the chagrin of Sandra Palmer. Ahmed Amar implements Abu Fayed's plan in the suburbs.
Presented with the evidence of Olivia's actions, PresidentAllison Taylor is forced to make a decision between her family and the Presidency. Thanks to Kim Bauer, Janis, Renee, and Chloe are able to save Jack and arrest Tony before he can kill Alan Wilson. With Wilson refusing to talk and Jack about to die, the fight is no longer in the field, it's for the hearts and souls of Jack and Renee.