Seasons 1 to 4. Season 1 begins with Jack Bauer, a Federal agent who heads up the Counter Terrorist Unit. He is given the task of preventing an assassination attempt on Presidential candidate, Senator David Palmer. The 'assassin' is believed to be working on the inside of the Government and Jack may trust no-one. When Jack's family are abducted and the authorities suspect Jack of attempted murder, he turns to colleague Nina Myers who is his friend and confidant... Filmed in real time, Jack faces the worst twenty-four hours of his life as he battles for the recovery of his family and a government mole.