Keifer Sutherland as Jack Bauer in "24" (File Photo)

The clock for "Day 6" of Fox Network's Emmy-winning series "24" began ticking on Sunday at 8 with two one-hour episodes, to be followed by another two-hour thriller Monday at 8, on Jan. 22.

Many "24" addicts who had been counting down the days until the show returned knew generally what's going to happen: the world will be put in peril by evil men and Jack Bauer will be called upon to save it, most likely at great cost to himself and greater cost to those who cross him.

Every new season of this Fox thriller is another twist of a kaleidoscope: the same pieces -- terrorists; counter-terrorists; an innocent suburban family; and the president, his aides and his family -- are tumbled together to form new patterns around the central figure of the special agent Jack Bauer.

"Day 6" opens with a bus explosion on a busy L.A. street, leaving 23 dead, including the suicide bomber. U.S. government intelligence reports indicate the attacks are being ordered by Middle East tyrant Hamri Al- Assad (Alexander Siddig, "Syriana"), who for 20 years has been calling for the destruction of the United States.

What follows is a procession of bloody killings, torture, unlikely alliances, bad decisions, bungled operations, a shocking shooting and unimaginable deals -- like freeing 110 terrorists, one of whom knows how to activate a "suitcase" nuclear bomb.

And, for the first time, Bauer is so overwhelmed by what he is forced to do (including one unimaginable act that makes him fall to his knees and vomit), that he begins to doubt his ability to continue.

"Tell the president I don't think I can do this anymore," he says to Buchanan, "I'm done."

But after Monday night's jaw-dropping final scene, America will need him more than ever.

Editor: Donald