Day 4 starts and ends at 7:00 a.m. It has been 18 months since Jack Bauer averted yet another deadly crisis in Los Angeles. Subsequently, he was fired from CTU by the new director, Erin Driscoll. He now has a new lease on life as a senior advisor to Secretary of Defense James Heller. He has also found a new love in the form of his boss's daughter, Audrey Raines. But, an impending hostage crisis concerning his latest boss leaves Jack's new life in shambles. Jack finds he must go back to his old calling as a CTU agent in order to save the life he has made for himself. As the day unfolds several contingency plans are revealed, all devised by Turkish terrorist Habib Marwan. Each of Marwan's attacks proves even more devastating than its predecessor and CTU races to find him before he can unleash unprecedented terror upon America. To complicate matters, a secret Chinese Consulate mission goes wrong which sets up serious consequences for Jack in future seasons.