Season four of the wildly successful real-time adventure series 24 begins some 18 months at the end of season three. John Keeler (Geoff Pierson) has succeeded David Palmer (Dennis Haysbert) as president of the United States, and the new secretary of defense is James Heller (William Devane) -- who is also the new boss of crack CTU agent Jack Bauer (Kiefer Sutherland). One of Hellers first moves is to reunite Jack with his old nemesis Erin Driscoll (Alberta Watson), now the head of the CTU. Unbeknownst to most of the principal characters, Jack is in love with Hellers daughter (and policy assistant), Audrey Raines (Kim Raver), this despite the fact that Audrey is still legally married to estranged husband, Paul (James Frain). Outside of Jack Bauer and President Keeler, the only series character from season three to return as a regular in season four is CTU tech analyst Chloe OBrien (Mary Lynn Rajskub); the rest of the cast is virtually brand-new. The day that comprises the fourth season begins, typically, with a nail-biting crisis, when James Heller and his daughter Audrey are captured by a terrorist group headed by Habib Marwan (Arnold Vosloo), who has already set a fiendish master plan in motion with a train bombing in the U.S. It soon develops that the abduction of Heller and Audrey is but a subterfuge to allow an enemy stealth bomber to blow up Air Force One and eliminate the president -- and ultimately to gain control of a nuclear warhead that will destroy a major U.S. city. Making matters worse, there is a turncoat in the ranks of the CTU -- and without giving the game away, it can be noted that CTU agent Sarah Gavin (Lana Parrilla) tumbles to the moles identity before Jack Bauer does. As the tension mounts, Paul Raines is seriously wounded saving Jack during a covert mission, which ices Jacks relationship with Audrey; a shattering personal tragedy forces Erin Driscoll to resign from her post in mid-season; there is dissension in the terrorist ranks during a concerted effort to trigger nuclear meltdowns in six different cities; the seldom-used 25th Amendment is invoked to change presidents in midstream; and an old enemy of Jacks from the series first two seasons appears virtually out of nowhere to make a terrible situation far worse than could ever be imagined. Clearly, the fourth season of 24 drew inspiration from the headlines of the day, notably the controversial treatment of prisoners at Abu Ghraib. The series also was attacked by certain special-interest groups for making several of the villains Arabs, or of Arab descent. And of course, there were those who carped that the series notion of real time (each episode consisted of a single uninterrupted hour in the same day) resulted in some rather ludicrous lapses of logic. But 24 was as big a hit in the ratings throughout its fourth season as it had been all along. ~ Hal Erickson, All Movie Guide