Heroism doesn't pay. It's evident on the big screen, where a dour James Bond doesn't even take time to enjoy a decent martini, and it's even more so on the small screen, where most of today's protagonists begrudgingly save the day as if they're getting root-canal surgery.

I suspect that one of the reasons why CBS' "The Mentalist" is this fall's breakout series is that star Simon Baker unmasks the killer with a twinkle in his eye and a wisecrack on his lips. He's under the impression that serving justice is a hoot.

Try telling that to two of TV's most depressed, and destructive characters, Jack Bauer of "24" and Vic Mackey of "The Shield," who both get dragged back into the spotlight this week under very different, but equally harrowing circumstances.

You'll be forgiven if you don't quite recall the depth of their funks. "24" has been off the air for 18 months, and tonight's two-hour movie, which plays out in real time, is merely a bridge to the new season, which kicks off in January. "The Shield" has slipped in ratings and relevance in the past couple years, but Tuesday's 90-minute finale is a jaw-dropping reminder that it has consistently been one of our best and most brutal dramas.

"24" picks up three years after we last left Bauer (Kiefer Sutherland) gazing over the edge of a cliff and leaving us with the distinct impression that he might take a flying leap. Instead, he's been in self-exile, traveling the world in search of solitude and peace, much as David Banner did in the late '70s. Of course, he knows -- and we know -- that circumstances will eventually transform him back into the Incredible Hulk.

In this case, Bauer's inner monster is awakened by a violent coup in the fictional African nation of Sangala, where rebels are using children to fatten their forces. The victims include a group of children being nurtured at a school where Bauer happens to be hanging out with his special-forces buddy Carl Benton (Robert Carlyle, who looks about as formidable in action as Dakota Fanning).

It's inevitable that Bauer will have to help his friend, rescue the kids and shoot up dozens of evildoers. More important, at least to the nature of the character, is that Bauer has to withstand intense torture (this time around, it's a fire-baked scythe pressed to his stubbled cheek) and face a possible congressional inquiry into his own, um, unique interrogation methods over the years.

The story's second setting is Washington, D.C., where a new president (Cherry Jones) is about to be inaugurated, and it's here the action comes to a screeching halt. I'm sure the exposition will serve the series well when it returns in January, but for now it takes away from the sick pleasure of watching Sutherland squirm, spit, sulk -- and survive -- in the face of danger.

A dirtier Dirty Harry

Watching Vic Mackey twist in the wind is a much more complicated ordeal.

For six years I've rooted for the Los Angeles pit bull as he bit his way through red tape to rid the streets of drugs and thugs. He's the closest thing we've had to Dirty Harry for years, with one major distinction: He really is dirty. From the groundbreaking pilot, in which he shot a fellow officer in cold blood to protect his investments, to the finale, in which he commits an unforgivable betrayal, he's been the hardest hero to embrace -- and the most fascinating to watch.

Tuesday's episode, written by series creator Shawn Ryan and helmed by the director of the series' pilot, Clark Johnson (he also did the first and last episodes of the final season of "The Wire"), reveals the fate of Mackey and his fellow officers with the show's usual bluntness.

Who dies and who survives? I wouldn't dare tell, but I will reveal that the death of one character is so heartless and haunting that you'll shake in your sofa. As for Mackey, I predicted to diehard fans months ago that death would be too easy for such a complex character. I was right, but even I couldn't imagine the depth of his ultimate punishment. Michael Chiklis, who has played Mackey as a fast-thinking motormouth, is practically silent in the series' final half-hour as the weight of his Jenga-like setup comes crashing down. It's a whole lot more painful than being scorched with a blazing blade.

Watching Bauer and Mackey suffer through torture is can't-miss viewing, but do yourself a favor: Follow up these programs with a dose of Laurel & Hardy or, at the very least, an hour of "The Mentalist." You're going to need the sweet relief.

njustin@startribune.com • 612-673-7431