In his new movie, "No Way Out," starring Kevin Costner and Sean Young, director Roger Donaldson winds up a lot of clocks and sets them ticking, ticking down. The movie's plot is complicated; it has wheels within wheels, gears within gears. Set in Washington, it's based loosely on Kenneth Fearing's 1946 mystery novel, "The Big Clock," a vengeful blast of grape aimed at the venal world of magazines. But instead of the New York publishing scene, the movie's target is government and government officials. It's a story about sex and murder in high places, cover-ups and spies -- a Washington story.

The movie turns on the death of a young woman named Susan (Sean Young), a chestnut-eyed beauty, part deb, part call girl, who runs the Washington party circuit like a prize thoroughbred. The man enlisted to solve the crime is a pistol-hot naval officer, Lt. Cmdr. Tom Farrell (Kevin Costner), whose regular job is to serve as liaison between the CIA and Secretary of State David Brice (Gene Hackman). Brice and his assistant, Scott Pritchard (Will Patton), have initiated their investigation to find the murderer, whom they believe to be a Soviet mole operating inside the Pentagon.

At least, that's their cover story. What they're really trying to do is find the man who caught a glimpse of the secretary, who was having an affair with Susan, entering her apartment the night she was killed. But Farrell knows something they don't know; he knows the man who saw the secretary that night, the man who was also Susan's lover, the man he's been instructed to find. And he knows just where to find him. All he has to do is look in the mirror.

"No Way Out," which was adapted from the Fearing novel by Robert Garland, isn't a work of great originality or depth, and aside from a pro forma cynicism about politics and the private lives of politicians, it has hardly any politics at all. This isn't a movie you can assess in terms of relationships or ideas. And it doesn't want you to think much either (the details won't bear up under much scrutiny). But in thriller terms it's close to irresistible and enormously entertaining. And the movie's lack of weight is part of what makes it work, part of its gripping purity. What this movie, which as a political thriller has more in common with "Three Days of the Condor" or "Seven Days in May" than "All the President's Men," has going for it is a great premise: the mainspring of this big clock is built to run.

The notion of a man running an investigation that, unless he can uncover evidence to the contrary, will lead ultimately to his own destruction is sure-fire. Fearing's novel was adapted to the screen once before, in 1947, with Ray Milland and Charles Laughton in the starring roles. But that movie, which was directed by John Farrow and had a great, sputtering-gargoyle performance by Laughton, stuck closer to the original than this current version. And where Farrow's work was noir-ishly atmospheric, Donaldson's is brightly lit, open.

And yet it's no less claustrophobic. Donaldson and his cinematographer, John Alcott, turn the labyrinthian halls of the Pentagon into a funhouse maze of glass and fluorescent light. These corridors of power are see-through. But you're never sure of what you're seeing or whom to trust. And Donaldson stands back, shooting the action from a distance, dispassionately. He doesn't hype the imagery; it's a reporter's camera he's using here. And he's got a clean, clear, precise style.

He also has a nearly flawless sense of staging. In the early scenes, when he's giving us the details of the plot -- when, for example, he moves away from Washington and Tom Farrell's affair with Susan to his heroic exploits at sea -- the story bumps along noisily. (This episode, in which Farrell, who's been called back to duty at sea, rescues a sailor downed in a storm, is proclaimed a hero, and called back to Washington to join Brice's staff, is a brazen plot maneuver, pure and simple.) But once the main action is set in motion, his timing is razor-keen. He does a beautiful job of cutting on the run within these offices and hallways, and Alcott's camera is always on the move, backing up, tracking, swerving around corners. (This was Alcott's last film -- the movie is dedicated to him -- and it's a fitting signoff.) As the walls close in, the pace never flags.

This picture plays beautifully off the background of current events. And without dealing with real-life issues, it manages to give a sense of how things can really go wrong. In casting Gene Hackman as Secretary Brice, Donaldson has chosen a more human, more complex figure than the monstrously evil man Farrow had as his villain.

Hackman's Brice is more of a weakling than a monster, and there's something childlike and touching about the character's insecurity and inability to cope. At the same time, Hackman shows that Brice can be a man of principle -- he opposes a powerful senator (Howard Duff) and the head of the CIA (Fred Thompson) over the funding for a controversial submarine -- and the mixture is convincing, but Hackman is a little too recessive in the part. There's not a false note in his performance -- as an actor he may be incapable of false notes -- but the character as he approaches him doesn't stir anything in the imagination.

The real villain in the piece is the secretary's right hand, Pritchard, and it's impossible to watch his manipulations of Brice without thinking of a shrewd Iago and a slow-witted Othello. Pritchard, who's played as a homosexual, is fiercely loyal to Brice, but he's also deeply jealous as well -- of Brice and Susan and Farrell -- and the righteous unctuousness of Patton's performance is truly creepy. He's the ideal cleanup man -- smooth, efficient, amoral. Patton overacts -- he bites into his lines as if he's eating corn on the cob -- and he has a habit of widening his eyes into a cold, psycho's stare, but he's an electrifyingly unsubtle actor. When he's onscreen, the heat is turned up a notch.

Things cool off when Sean Young slinks into view. Lean and fine-chiseled, Young showed as the beautiful android in "Blade Runner" that she makes a fine camera subject, but she's yet to show any talent as an actress. As conceived, Susan is an alluring pragmatist whose love for Farrell makes her rethink her choices, but when she spouts her hard-edged lines, her worldly toughness seems unearned. It's all pouty attitude.

As Farrell, Costner fares better. He hasn't had much opportunity to show himself as an actor, and he doesn't here either, but as a romantic lead, he has real substance, and with his cowlicky tufts of hair springing out of control, he's not so good-looking that he overwhelms the character. He's at his best here when he's allowed to swagger. In these scenes, like the one in which he first meets Susan, you can feel his confidence in himself, his cocksure roguishness, coming through.

Costner doesn't have the lines here, but as he showed in "Silverado," he's so physically expressive that he doesn't really need them. And the combination of sexual self-awareness and introspection -- because he's in danger of being found out, he's always having to keep a close check on himself -- is what makes the character engaging. He's shifty, without ever seeming so. But we can never really get a fix on him.

The change of venue from New York to Washington, as it turns out, was the filmmakers' real stroke of genius. Where else but in Washington -- and present-day Washington, at that -- could a plot this knotted with improbability, this convoluted, this mad be set without provoking heehaws of disbelief. And still the mind boggles at the unlikeliness of the terrain as corner after strange corner in the story is turned. The impulse, when faced with circumstances this baroque -- especially the movie's final twist, which the film company has begged critics not to reveal -- is to throw up your hands and dismiss them out of hand. And you still may be tempted to, until you think about what's been happening lately on the Great Stage. Until you remember the Bible. And the cake. And the security fence ...

Plausibility doesn't count for everything in a thriller, but it counts for something. The question this picture begs is whether or not such a thing as an implausible scenario in the world of politics exists anymore. What with things as they are, it's hard to count out even the most ludicrously exaggerated premise. The paucity of imagination exists onscreen and on the page; fiction can't seem to keep pace with fact. And since we see real events through television as theater, how can we be satisfied by fictional dramas and intrigues? How could created characters rival, in sheer outrageousness if nothing else, the ones that already exist in the flesh?

These days Washington is just naturally surrealistic; anything can happen and life goes on. Ultimately, "No Way Out" seems unlikely only when compared with other movies, not real life. Nothing, it seems, is harder to swallow than that. No Way Out, at area theaters, is rated R and contains some nudity and scenes of violence.