Jack Bauer endures the elements and fights on to prevent an attack that could change the country forever. As the catastrophic blow to the nation nears, Tony Almeida operates from the field and Kim Bauer, who was last seen in Season Five, returns. Meanwhile, the stakes are raised when the administration is faced with a blackmail scenario.
Walt returns to work. Skinny Pete gets ripped off and when Jesse steps in to « handle it, » he gets more than he bargained for. Skyler finally gets to thank Gretchen for paying for Walt’s treatment.
When a traitor is discovered inside the Dollhouse, Echo and Sierra are programmed as spy hunters to uncover the culprit. Meanwhile, Ballard receives surprising news from Mellie, and Adelle harbors a secret.
Cal and Gillian assist FEMA in their investigation of a building collapse and uncover a massive cover-up. Meanwhile, a billionaire asks Ria and Eli to determine if his girlfriend loves him for the right reasons before he proposes.
Tommy copes with the loss of his father and a new man in Janet's life. Sheila finds a different way to deal with her issues while Sean, Franco, and Mike concoct a surefire way to get rich and laid.
Patrick Jane and the team go to Hollywood when they investigate the murder of a movie producer.
Just seconds before a building is demolished, a mysterious mute child that has been living alone underground is discovered. When the FBI’s Fringe Division investigates, the boy forms an unspoken connection with Agent Olivia Dunham. Meanwhile, an especially gruesome serial killer resurfaces and showcases his “artistry” by displaying his work publicly. As the boy gradually assimilates into a new environment, Olivia and the team must race against the clock to prevent the mad man from causing further massacre.
Castle and Beckett investigate the murder of a women found frozen and tangled in steel bars at a construction site. The case leads them to look into an old case and also has Beckett thinking about some memories of her past.
As Danko spearheads the government operation, someone close to him is put in the line of fire. HRG’s life continues to spiral out of control and his marriage is dangerously close to the breaking point. Meanwhile, Hiro and Ando continue their road trip with a special delivery for Matt Parkman. Elsewhere, Angela Petrelli unearths the demons of her past.
As the day stretches into the middle of the night, Jack and the FBI formulate a plan to prevent further terror attacks. Events take an unexpected turn when the politics surrounding the administration expand beyond the White House.