BEIJING, Jan. 16 -- After four seasons of non-stop action and a growing audience, "24" starts up its fifth season with a two-night, four-part marathon on Jan. 15 (Sunday and Monday, 8 o'clock, EST), with the suggestion that it may be better than ever.

Characters of "24" 5th season

    Once again, the folks behind it have reassessed the trials and tribulations of Jack Bauer and created a gripping variation on the show's format.

    When "24" first began its run on Fox back in the fall of 2001, there were considerable doubts that it would last past mid-season.

    However, over the last four years ¡ª one day at a time ¡ª the superhero of Fox's "24" has saved humanity from terrorists, beaten confessions out of close friends, battled heroin addiction, discovered his murdered wife's body, and, last year, even faked his own death. All with little regard for himself.

    Kiefer Sutherland is back as Jack Bauer, a crack but controversial US federal agent who, at the conclusion of the fourth season, had faked his own death and was walking off into obscurity. Only four people in the world knew that Bauer actually had not been killed.

Superhero Jack Bauer (Kiefer Sutherland)

    "This time, something happens to Jack on a very personal level that pisses him off," says Kiefer Sutherland. "Because he's presumed dead, a lot of the boundaries he was restricted by ¡ª by virtue of who he was working for ¡ª simply don't exist now. And he's mad."

    When first we see Bauer in "24" fifth season, 18 months have passed. He has a new name and is living a non-descript life, working irregular shifts at an oil field and renting a room in a home with a single mom and her teenaged son.

    Until now, Sutherland has only subtly allowed the stress of selflessly saving the world to show on Bauer's boyish face. This season, however, besides being cranky, our clean-cut action hero is looking downright disheveled.

    "The weight on people who are responsible for making decisions that affect so many lives, you can only imagine what that must be like ¡ª putting 10 lives at risk to save 1000," the actor says.

Chloe O'Brian	Diane Huxley	Tony Almeida

Click next page to see who's back and who's new for Season 5