Jack Bauer has a final confrontation with Ira Gaines as he saves his family with Rick's help. David Palmer plans to talk to the D.A. about Dr. George Ferragamo's murder, Carl Webb changes his mind. At CTU, Nina Myers discovers that a second assassin has arrived in LA, which means that Palmer's life is still in danger.
George refuses to allow Jack to assist in Nina's interrogation. Jack resorts to blackmail to change George's mind. Palmer and Stanton meet with a Middle Eastern ambassador who may be in league with Second Wave. Tony visits the Warner home and questions Reza about his possible connection with Syed Ali.
Jack and Chase track down the last vial and Chase makes an incredible sacrifice. Gael's devastated wife visits CTU and seeks vengeance on Saunders. President Palmer makes an unexpected announcement after Sherry's death. The day's events take a toll on Jack.
Jack successfully rescues Secretary Heller and Audrey. CTU realizes that the train bombing was a cover up for a much larger attack. Dina's commitment to her cause is tested when Navi reveals his plans for Behrooz.
Jack meets with Mike Novick in hopes of gathering evidence against Cummings. Martha begs Aaron Pierce for help while Walt thinks that he is forcing Logan into aiding him with his complicity with the terrorists. Buchanan butts heads with Lynn McGill over a decision to violate the President's orders, while the Russian separatists attempt to escape with the nerve gas.
When threatening the Prime Minister's security guard doesn't work, Jack uses the ventilation system to smoke the couple out of their safe room. Henry Taylor discovers that his primary Secret Service guard is involved with the conspiracy. Renee gets captured while searching for Bauer and Emerson orders Jack to kill and bury her.
With the evidence in hand, Jack Bauer contacts Meredith Reed and asks to meet her, so that she can help expose those responsible. However, CTU intercepts the call, which allows Jason Pillar to assist Pavel Tokarev and his men plan an ambush for the two of them. Arlo Glass secretly teams up with Chloe O'Brian in order to find the identity of an old contact who is aiding Jack.
After escaping from the CIA, Jack tracks Chloe O'Brian back to her new family's hideout and reveals his objective in London. To placate the British, PresidentHeller orders the interrogation of the drone pilot supposedly behind the attack in Afghanistan. Meanwhile, the real culprit completes work on a device that will grant its buyer control over several more drones.
At CTU, Tony is warned of an attack on a Los Angeles Metro station and goes to prevent it. CTU is attacked by an EMP bomb and terrorists take agents hostage.
