Moments after discovering his daughter, Kimberly, has snuck out of the house, Jack Bauer is called into work. As head of the CIA's Los Angeles Counter Terrorist Unit office he's told that an assassination attempt will be made within the next 24 hours on the life of presidential candidate David Palmer and it's up to his team of agents to keep Palmer alive. Meanwhile, Jack's wife, Teri, sets out to find their daughter.

Teri receives a phone call from Alan York who says his daughter, Janet, is a friend of Kimberly's and is also missing, so the two parents join forces to try and find the girls. Even as Jack is secretly called out of the office and given an encrypted key card containing information on the Palmer hit that could lead him to a dirty agent within his organization, the explosion of a 747 over the Mojave Desert becomes yet another piece in the puzzle.

Kimberly and Janet realize they are in danger after it becomes clear that their two dates have kidnapped them. Despite the threat on his life, Senator Palmer sneaks out of his hotel to meet a reporter who has damaging information that could affect his campaign. Back at the office, Jack has Jamey, a member of his team, decrypt the key card.

Convinced Jack needs to be relieved of his command, one of his team members, Tony, calls George Mason who arrives and puts the CTU under lock-down. With the help of his second-in-command, Nina, Jack slips out and heads for an address listed on the key card. Once there he encounters a shooter who hints that Kimberly's disappearance is part of a bigger plan. Meanwhile, the two boys deliver Kimberly to a man named Ira Gaines.

Jack follows the arrested shooter to the police station in hopes of interrogating him only to find that Mason has arrived and taken control of the situation. But when the shooter says he will talk only to Jack, Jack learns he must break the shooter out of jail in order to learn who has kidnapped Kimberly. Back at the hotel, Senator Palmer learns more about the threatened news leak that could hurt his campaign.