In the first 10 minutes of last year’s enormously popular, Emmy-winning fifth season of “24,” the show’s writers killed off two principal characters and maimed a third, leaving him mostly dead until they could finish him off a few hours later. Now, having proven their ruthlessness toward the show’s dearest fixtures, the writers are clearly hoping we’ll watch Jack’s latest brush with death and think, “Hey, maybe those crazy bastards will actually do it.” The problem is, we all know that Jack Bauer is the one piece of fine china that Fox simply isn’t going to break, and not just because Sutherland still has three years left on his contract. Jack Bauer is “24,” and television networks aren’t in the habit of driving their lucrative franchises into the ground.

Jack Bauer is the biggest, baddest action hero in the country right now, an unprecedented feat for a television character. No one—not James Bond, and certainly not Spider-Man—has more street cred with the American male population. (And sorry, ladies, this is going to sound sexist, but we choose the action heroes around here.) As the show’s audience has grown, Bauer has evolved from hero to superhero, making him more or less invincible. During the sixth season’s first hour, we learn that Jack has spent the past two years getting pummeled in a Chinese prison, and he didn’t give up a single secret, didn’t say a word, even though we’ve been told many times, on this very show, that everyone cracks under torture eventually. But not Jack, no way.

All of which makes the first hour of the new season a complete waste of time—easily the most irritating episode of “24” yet. There’s no point in getting emotionally invested in the prospect of Jack’s death, so the entire episode is just a dull exercise in waiting for him to make his narrow escape so he can get on with the business of tracking down, and kicking the ass of, whoever put him into this pinch in the first place. (And by the way, if you consider that a “spoiler,” you’re too gullible to be watching “24.”)

Fortunately, Fox provided critics with the first four hours of the new season, which will be shown in two-episode chunks this Sunday and Monday night, and the subsequent three hours are vintage “24”—thrilling, frightening, provocative and patently ridiculous. One of the qualities that has made “24” among the most memorable TV dramas of its generation is that it has stamped itself as the show where stuff actually happens . On other shows, and often in the movies, the hero snips the blue wire just in time. On “24,” the bomb often goes off, the nerve gas gets out, presidents get shot, good guys get killed and the terrorists win, if only for a little while. And before you can catch a moment to roll your eyes at the absurdity of it all, the show is onto the next crisis. On “24,” the plot is a perpetual forward-motion machine. It never stops. It never even slows down.

It’s also, at its best, bracingly topical. Depending on your perspective, “24” is either a neocon sex fantasy or the collective id of our nation unleashed. The show debuted just a few months after 9/11, and its watchful, paranoid visual language was forged in that moment. The very first episode featured a terrorist blowing a plane full of passengers out of the sky. Subsequent story lines about Islamic fundamentalism, the torturing of innocents, biochemical attacks and atrocities broadcast over the Internet felt like they were ripped from the front page of The New York Times. The writers of “24” have always proven willing to brush aside an audience’s natural desire for relief so they can explore the murky, anxious territory of postdisaster scenarios. What happens after the nerve gas gets out? What happens after the president’s jet gets shot down?

The balance of public opinion seems to be against me, but I thought “24” took a wrong turn last year in its fifth season with a story line that was too outlandish even by its own standards: a president who was not only incompetent but traitorous. It was intriguing notion, but one untethered to the real world. Only a pair of bravura performances by Gregory Itzin as President Logan and Jean Smart as his First Lady kept the show from going off the rails completely. In season six, “24” is back to probing our subconscious fears for new nightmares. At a moment when President Bush is squeezing our civil liberties to fight a war on terror, the writers of “24” have come up with a story that asks whether something could ever happen here in America that makes civil liberties a luxury we can no longer afford. Some critics will surely complain that the show is mindlessly upping the ante, but they’re missing the point. The folks behind “24” have never been interested in the ante. They’re interested in what comes next.