Say something happened to you, some time ago, you’re not sure how long, and now you can no longer remember anything for more than a few minutes. You still remember how to speak, how to read, how to turn a doorknob; you just don’t know how you got here, why is it you’re doing what you’re doing now. So you take pictures, and you take notes, to remind yourself: You’re after the man who killed your wife.

Memento begins with a killing, and very stylishly splits off into two threads, one moving forward from the past, the other backward from the killing itself, spiraling like a narrative DNA helix. Even as you try to arrange the scattered pieces of the jig-saw, the mood suddenly shifts between drama, tragedy, and occasional pieces of humour. Like the protagonist, you constantly find yourself in a sudden and unexpected situation; unlike him, you can manage, if you try hard enough, to see the bigger picture.

Guy Pearce (The Time Machine) gives a riveting performance as the tortured protagonist, with support from Joe Pantoliano and the delectable Carrie-Anne Moss (both were in The Matrix). The supporting characters each orbit around the star like unpredictable moons, leaving you to figure out, between mercurial impressions, whether they are helping him or directing his vengeance toward their own ends.

The script, adapted by director Christopher Nolan based upon a short story written by his brother, Jonathan Nolan, won an award for Screenwriting at Sundance, and garnered a nomination for Screenplay Written Directly for the Screen at this year’s Oscars. The movie itself, amazingly shot in only 25 days, was nominated for Sundance’s Grand Jury Prize and Best Editing at the Oscars.

As Nolan’s first Big Film, Memento is noticeably lacking in any semblance of a marketing effort. As amazing as the film is, however, the fact that it is based upon a gimmick does cast a shadow of doubt on whether he can repeat his success, though the fact that Al Pacino, Robin Williams and Hilary Swank are starring in Insomnia, his next movie, does show a certain measure of faith.

Except for the movies of M. Night Shyamalan, we haven’t had an excellent thriller since around 1995 (The Usual Suspects, of course; Shallow Grave, Se7en), and it’s about bloody time Memento came along to end the drought.

The Region2 and Region4 DVDs have an edited version of the movie with the scenes in chronological order.