Want to know how to snap a physically and mentally exhausted hero back to life? Try whispering this in Jack Bauer's ear: "You will die for nothing."

By now, any evil terrorist should know better than to taunt 24's mythic warrior (Emmy champ Kiefer Sutherland) this way. When it happens, near the end of the first hour of 24's darkest and most unsettling season yet (premiering Jan. 14 and 15 at 8 pm/ET on Fox), Jack awakens with a bloody vengeance.

But this isn't the same old Jack. This Jack is damaged goods, reeling from nearly two years of torture in a Chinese prison where he uttered nary a word. Now, when he speaks, he says things like, "I don't know how to do this anymore." Say it ain't so.

Making matters worse — something 24 does fiendishly well — the U.S. has suffered in Jack's absence, victimized for 11 months by explosive terror attacks. Citizens are at risk not only from suicide bombers but from government bureaucrats trampling civil liberties.

There's a new President Palmer, David's brother Wayne (DB Woodside), but that comfort is negated by an adviser (Peter MacNicol) who "treats the Constitution like a list of suggestions," according to one of his critics.

24's first four hours, airing over two nights, aren't quite as electrifying as last season's opening act. CTU is less fun minus some of last year's casualties, and watching Chloe's ex, Morris (Carlo Rota), squabble with middle manager Milo (Eric Balfour) is truly tiresome.

But none of these problems diminish the pulse-pounding pleasures of watching 24. The nastier things get — and by the end of the fourth hour, this day is an absolute nightmare — the more we love it and dread that moment when the clock strikes a new hour, signaling the episode is over.

Bloody Empire
All of the deadly sins, including a few you never imagined, are alive and well in HBO's Rome (Sundays, 9 pm/ET). Returning for a second and final season, it's like Dead­wood in togas, a violent and bawdy tapestry of a vanished civilization. (If you can call this civilized.)

The new — and often jarringly disjointed — season picks up after Julius Caesar's assassination, as treachery vies with debauchery for the national pastime. Rome splits its focus between high and low society, with Dynasty-style intrigues in the homes of Caesar, Brutus and Marc Antony often upstaged by the earthier drama among the lower-born Romans.

The hero of the piece is Titus Pullo (Ray Stevenson), a brawny soldier who stays loyal to his brooding buddy Vorenus (Kevin McKidd) throughout his many fits of pride and rage. It takes a while for Vorenus to snap out of his funk, stewing in guilt over the death of his wife and the abduction of his children. But when he does, heads literally roll.

Ah, those were the days.