Al Pacino being dragged off to do Godfather IV.

Insomnia is a compelling thriller, directed by Christopher Nolan, writer-director of last year's mind-bending Memento. He tells the story forwards this time, but what the movie lacks in temporal gymnastics it makes up for in characterization and atmosphere.

The story: two Los Angeles homicide detectives travel to the small, northern Alaska town of Nightmute. Ostensibly they're there because the chief of police — an old friend — needs their help on a murder investigation, but they're more than happy to get out of the city and away from a sticky internal affairs investigation that's getting uncomfortably close to them.

The cops are Will Dormer (Al Pacino), the grizzled, savvy veteran, and his partner Hap (Martin Donovan). During a stakeout gone wrong, Will makes a tragic mistake, which he blames on the fleeing killer. But there's one witness to the incident: the killer himself. He starts phoning Will, essentially blackmailing him into pinning the murder on someone else. The rest of the movie is Will struggling to keep the wrong guy from going to jail, trying to keep his own name clear, and battling insomnia brought on by his guilty conscience and exacerbated by the 24-hour Alaskan daylight.

"Yeah, I was in The Devil's Advocate. You wanna make something of it, Mork?"

Don't bother scrolling down; I'll tell you right now this is my first 4-banana movie of the year. It's all good news this time, starting with the script by Hillary Seitz, based on a Norwegian movie of the same name. Every plot point, every character feels like it belongs in the story and serves a purpose. Suspense builds as we watch Will try to save his own career without sacrificing his case. Characters are revealed through sharply written dialogue and small, telling actions.

Add to this a trio of fine performances by past Oscar winners. Hillary Swank shines as a dogged young detective, in awe of the legendary L.A. cop she's working with. Robin Williams plays the killer's banal, selfish evil to perfection. Pacino as the conflicted center of the story, takes Will Dormer from weary to ragged to a near total wreck, and does it with surprising understatement. He shows more with his eyes and slumping posture than many actors give us with pages of dialogue.

Director Nolan lives up to the reputation he created for himself with Memento. He displays a flair for action and suspense, particularly in an exciting chase scene across floating logs. The Alaskan setting is used to great advantage, especially in the fog-shrouded stakeout scene. The whole movie, in fact, takes place in misty daylight, never dark, never bright, its shades of gray echoing the moral ambiguity of its main character. It makes for a rich, satisfying story, one that's well worth seeing.

Gorilla Pants rating: 4 out of 4 bananas