You're not supposed to find belligerent drunks hilarious. Nor should you chuckle at gunshot executions or sliced thumbs. But "The Ice Harvest" doesn't take its moral measure in the real world. This often macabre comedy, which stars John Cusack and Billy Bob Thornton, allows us to doff such civilized traits as taste and decency. We're free to laugh at anything, and we do. Oh, the shame -- and the good time.

It's Dec. 24 in Wichita, Kan., and the Midwestern city is slipping and shivering under the chilly blast of a sudden ice storm. The timing is disastrous for Charlie Arglist (Cusack), an unscrupulous lawyer who was planning to skip town with the $2 million he embezzled from mobster Bill Guerrard (Randy Quaid). Now, Charlie and his partner-in-crime, Vic (Thornton), are forced to sit things out, passing nervous time in the strip clubs, dank bars, restaurants and massage parlors that are their regular domain in this film-noirish world. (Vic's qualifications for this larceny? He runs a pornography business and his chutzpah helped Charlie go through with this crime.)

It seems their crime wasn't as flawlessly planned as Charlie thought. Roy (Mike Starr), a hit man for Guerrard, has been leaving emphatic messages on their cell phones. He's looking urgently for Charlie and Vic -- and not because he wants to kiss them under the mistletoe.

What to do? Charlie moves restlessly from place to place, trying to lie low. But he's doomed to be caught. He gets roped into ushering around his friend Pete (Oliver Platt), who loves to get drunk and draw attention in public places. And he's hopelessly in love with Renata (Connie Nielsen), a strip club owner and femme fatale he hopes to persuade to run away with him. Meanwhile, Vic may be cooler under pressure than Charlie, but he's no better at staying out of trouble. It isn't long before they're both fighting for their lives. If that takes a killing here, a drowning of bad guys there, well, that's the way of this world.

Director Harold Ramis -- whose long list of co-writing credits includes "Animal House," "Ghostbusters" and "Groundhog Day" (which he also directed) -- shows he's more than a slapstick-meister. Not only does he give the performers the comic space they need, he's also sure-handed with the atmospherics. "The Ice Harvest," something of a companion piece to the Coen brothers' "Fargo," is etched in bluish, chiaroscuro light, and the landscape is every bit as stark and haunting as the Kansas countryside in "Capote."

Screenwriters Richard Russo (also a novelist) and Robert Benton (director of "Places in the Heart" and "Kramer vs. Kramer") collaborated on the satisfying "Nobody's Fool," about a flawed man (Paul Newman) seeking redemption in a New England town. "The Ice Harvest," based on the novel by Scott Phillips, amounts to a slam-dunk for them. Once again, they evoke the stifling atmosphere of a small town and the jaded but funny souls imprisoned in it.

When Vic succeeds in forcing Roy into a trunk, for instance, the hit man tries everything to bargain his way out. First, he threatens to kill Charlie, who is also there, then promises to spare the lawyer's life if he releases him. When Charlie reminds Roy of his previous threat, Roy falls silent for a moment.

"I didn't mean it," he says.

Cusack is characteristically likable as Charlie, a tortured semi-loser with a glint of hope: If he just pays attention to his finer instincts, and if he's lucky enough, he might get through this ordeal alive. Thornton, who has made a career playing hangdog misanthropes, is a sullen delight as Vic, a schemer untroubled by such things as conscience.

If Cusack and Thornton are meant to be the stars, no one gave Platt the memo. His comedic talents have been evident only passingly, in roles such as the harried father in "Pieces of April." But here he busts loose. Sure, it's every actor's cheap and easy dream to play a drunk, but Platt pours human tonic into that glass. In one scene, he's taken with an attractive bartender and describes a sexual dream he fully intends to have about her. His language has its coarse imagery but there's a misguided romantic streak in there, too. You can't help liking this guy. When he gets what he deserves from the bartender's angry boyfriend, Pete picks himself up from the street outside, torn and battered.

"That was unpleasant," he observes. "I think I scraped my tummy."

While those other guys are fighting for the money, Platt's busy robbing something else: the movie.

Ice Harvest (88 minutes, at area theaters) is rated R for strong violence, nudity and profanity.

John Cusack wants strip club owner Connie Nielsen to run away with him.Billy Bob Thornton, left, and John Cusack are a pair of likable rogues trying to pull off a theft in the face of an ice storm in "The Ice Harvest."