Counter-terrorism agent Jack Bauer fights the bad guys of the world, one day at a time. With episodes unfolding in real time, "24″ covers one day in the life of Bauer per season. After foiling a political assassination, stopping a nuclear attack and fighting bioterrorism, season four finds Jack working for the Secretary of Defense (while dating his daughter) as a terrorist sleeper cell in Los Angeles activates a plan it hopes will "change the world."