Spoilers for this episode.
Jack Bauer is answering Senator Blaine Mayer's questions about torture when Renee Walker arrives with a subpoena. The FBI needs his help investigating advanced technology thefts and the kidnapping of Michael Latham, who designed a firewall protecting national infrastructure. Renee shows Jack a photograph of Tony Almeida. Jack believed Tony was dead, but the FBI has checked his grave and found someone else's body. Tony's crew forces Latham to repair a device that breaches the firewall. Once it works, they gain access to air traffic systems. President Allison Taylor is preparing military action against General Juma's regime in Sangala, despite resistance from her advisers.
Henry Taylor pursues a separate suspicion that their son Roger was murdered. An investigator has found a payment to Roger's girlfriend, Samantha Roth, and Henry wants to confront her. Jack identifies Gabriel Schector as a supplier who once worked with Tony. Renee takes Jack to question him, but a sniper kills Schector and his bodyguard just as Schector agrees to talk. Jack suspects someone inside the FBI exposed their visit. Tony calls to warn him away, then cuts off Jack's questions. As the hour closes, Tony's crew redirects a passenger flight toward a dangerous landing approach, demonstrating that the breach can reach aircraft already in the air.