Jack, Kate, Yusuf, and Wallace fight to escape from a deadly band of commandos. Palmer decides to take a stronger stance against the civil unrest resulting from the bomb explosion. Tony's trust in Michelle is broken when he suspects her of betraying him. Kim's worries seem to be over when she learns the charges against her have been dropped.
Nina gives CTU a phone number that ends up initiating a computer worm. Chappelle detains Chloe when she refuses to discuss the baby, but releases her to deal with the computer crisis. Sherry goes to see Julia, but ends up confronting Alan.
Chloe is forced into the field to draw intel from a computer when a woman reports that her boyfriend may be part of the terrorist conspiracy. CTU's efforts to apprehend Marwan are botched when the Secret Service arrives to arrest Jack for torturing Joe Prado. Mike Novick suggests bringing in someone who has experience dealing with terrorist attacks. A nuclear warhead is stolen in central Iowa.
While Jack comes closer to obtaining the recording from Christopher Henderson, tensions at the President's retreat escalate as Martha grows suspicious of her husband. Meanwhile, Heller and Curtis help in the struggle against Henderson. A surprising new ally joins Buchanan and O'Brian as they continue to assist Jack, and a new antagonist is revealed.
The Russians learn too quickly that the Chinese have the circuit board, leading Noah Daniels to suspect a spy. After some investigation, Daniels and Lennox plot to pass misinformation to the Russians through this unsuspecting informant. Nadia struggles with her newfound leadership at CTU when Division and Jack argue on how to handle the traumatized Audrey Raines. Cheng discovers the circuit board is damaged.
Tony destroys the canisters. With his leverage gone, Jonas Hodges is taken into custody at the White House. Jack reconciles with his daughter, Kim, but refuses to agree to a possible treatment for his condition that might put her at risk. Larry Moss pursues a rogue Starkwoodoperative by chopper, but is met with a stunning betrayal.