Insomnia” is not “Memento.” Christopher Nolan’s second film was acclaimed for its complex, inverted setup; his newest follows a more standard structure. “Memento” starred actors on the fringes of Hollywood’s “it” list; “Insomnia” stars some of the biggest names in show business. Like “Memento,” “Insomnia” deals with the motives behind crime. Unlike “Memento,” “Insomnia”‘s treatment of its subject is conventional.

But that doesn’t make “Insomnia” any less stunning. Though it may be made for a broader audience, “Insomnia” remains several notches above other Hollywood thrillers, exploring provocative themes of invented truth and selective memory.

Based on the 1997 Norwegian film directed by Erik Skjoldbjaerg, the film tells the tale of two Los Angeles Police Department officers who are sent to the sleepy Alaskan town of Nightmute to investigate the murder of local teen-ager Kay Connell. Will Dormer (Al Pacino) and Hap Eckhart (Martin Donovan) are hardly upset about their assignment, eager to escape an inquiry from the LAPD internal affairs division that threatens to unravel a lifetime of work.

But things take a turn for the worse when, while chasing a suspect, Dormer fires his gun into the fog and kills Eckhart. Instead of admitting his mistake, he lies, attempting to pin the blame on the man who killed Kay Connell.

The problem? The only witness to the crime is Walter Finch (Robin Williams), the man who killed Kay Connell.

Dormer’s lie sets off a chain of deceptions. To maintain the appearance of innocence, he spends his days fabricating evidence, forcing confessions and keeping up the appearance of a police officer investigating a brutal killer. He spends his nights awake under Alaska’s Midnight Sunday, haunted by visions of his partner’s face, flashes from past crimes and his own guilty conscience.

It’s a good cop/bad cop story – except the lines between good and bad are blurred beyond recognition. Young local cop Ellie Burr (Hilary Swank in her best performance since “Boys Don’t Cry”) suspects Dormer is not telling the truth, but he has covered his lie so well that she must struggle for every scrap of evidence against him. And Dormer forms an uneasy alliance with Finch, realizing that Finch’s actions are not so far from his own. By movie’s end, “Insomnia” has become a a chilling exploration of guilt and a haunting meditation on truth.

“Insomnia” maintains a level of intensity rare in most Hollywood films. The pacing is similar to that of “Memento,” and the composition of the shots keeps viewers on edge. Cinematographer Wally Pfister, who served the same role in “Memento,” brings many of his old techniques to “Insomnia” – a scene of Dormer walking down a narrow hallway, for example, will show him from the front, then the back, then the front again, quickly cutting between the shots to show viewers the world from Dormer’s perspective. And the score, composed by David Julyan (who also composed the music for “Memento”), pulses and swells as the movie progresses.

Though the movie unfolds chronologically, Nolan doesn’t fully shed his flashback techniques from “Memento.” In fact, the scenes focusing on Dormer’s sleepless nights – during which he sees scenes of past and present crimes mixing with the image of Eckhart’s face – are some of the movie’s strongest.

Also strong is Pacino’s performance. As he becomes aware of the consequences of his lies, he begins to look more and more haggard, to act more and more on edge. For the second half of the film, Pacino seems just on the cusp of losing it as his character’s actions become desperate.

But the most impressive and most surprising performance comes from Williams. He’s downright creepy as a police novelist who “crossed the line” into murder. Every line is delivered with earnest; his features seem harmless one moment, distorted the next. When he says his crime was an accident, he seems less like a cold-blooded killer and more like a reclusive middle-aged man who could never be provoked to kill.

The only disappointment in the movie is its ending, which comes close to a standard shootout. For all its hinting at greater themes, the movie’s last five minutes seem too contrived. Considering that the some of the best scenes in the movie are those that show Dormer struggling with his conscience and with the consequences of his actions, it’s a shame Nolan chose an ending that gives Dormer an easy out.

But even then, “Insomnia” maintains its tension. Nolan may resort to a standard Hollywood ending, but it’s still a remarkably well-written, well-staged and well-filmed standard Hollywood ending.

That’s one of the most peculiar things about “Insomnia.” Far from original, it borrows heavily from cop movie conventions – but Nolan manages to take standard devices and give them his own twist. “Insomnia” may be less inventive than “Memento” – but it’s no less captivating. nyou