By OnMilwaukee Staff Writers   Published Apr 12, 2001 at 3:18 AM

Sometimes the best movies are the ones you have never heard of. Such is the case with "Memento," a new film starring Guy Pearce, Carrie-Anne Moss and Joe Pantoliano. Prior to its world premiere at the Toronto International Film Festival last year, no one knew anything about this riveting little gem. But the buzz soon spread throughout the festival...and rightly so.

Pearce, seen last year in "Rules of Engagement," stars as Leonard Shelby. Leonard wears a nice, expensive suit and drives a Jaguar but he is living in shady motels around L.A. He is on a mission to find his wife's killer, a mission that is truly impossible because of a rare condition from which he suffers.

The night Leonard's wife was raped and murdered, he hit his head badly while trying to rescue her. The result was a debilitating disease that completely erases his short-term memory. He can remember everything about his life right up until the moment he hit his head.

Because of this major problem, Leonard has devised a system that helps him remember things and piece together clues. He takes Polaroids of every place he goes and every person he meets. Then, he writes down any and all important information on the picture. He also tattoos vital facts on his body, getting a new one for every new fact. This helps Leonard but in no way does it make things easy.

Aiding Leonard in his task is a man named Teddy (Pantoliano), who claims to be a cop, and a woman named Natalie (Moss) who apparently is helping him because she also lost someone close to her. But can he trust either of them? Are they who they say they are?

If you miss a second of "Memento," you will be lost. The story is told in black and white and via countless flashbacks, first showing a scene and then the scene that led up to it. It takes place over a span of about three days, but moves seemingly reverse chronological order. Kudos to editor Dody Dorn for pulling off such a complicated job.

In "Memento," nothing is what it seems. It is gritty, sometimes dark and full of twists, but it is also mesmerizing and wonderfully told. It requires at least two viewings because no one will be able to figure out everything with only one. Sadly, this small movie won't be nearly as successful as "The Sixth Sense," though it is just as good.

Hopefully, "Memento" will earn the accolades it deserves, especially for Pearce. Already outstanding in the aforementioned "Rules of Engagement," "L..A Confidential" and the underrated "Ravenous," he again displays major star power. He is a classic hero here, tormented, edgy, mysterious and charismatic.

Do everything you can to see it as soon as you can and embrace it for the masterpiece it is. Don't let it fall through the cracks and receive a direct-to-video death. That would be a tragedy and a crime.

Grade: A

"Memento" opens Fri., April 13 at Landmark's Downer Theatre.