Dir: Christopher Nolan. US. 2000. 113 mins.

Prod co: Team Todd. Exec prod co: Newmarket. Backers: Summit Entertainment. Int'l sales: Summit Entertainment, tel: (1) 310 309 840001. Prods: Suzanne Todd, Jennifer Todd. Exec prods: Aaron Ryder, Will Tyrer, Chris Ball. Scr: Christopher Nolan, based on short story by Jonathan Nolan. DoP: Wally Pfister. Editor: Dody Dorn. Main cast: Guy Pearce, Carrie-Ann Moss, Joe Pantoliano, Jorja Fox, Stephen Tobolowsky, Harriet Sansom Harris.

Amnesia thrillers were big in the forties and fifties. British filmmaker Christopher Nolan's second feature (after the small but interesting Following) is a stylish revisitation of the genre - though as the hero never tires of repeating, it's not exactly amnesia that he suffers from - it's short-term memory loss. In other words, Leonard Shelby's memories fade after about ten minutes - and if he wants to keep track of names, faces and information, he has to make a note of them.

He does this in three main ways: taking polaroids of the people he meets, writing notes (sometimes on the polaroids) and - when something is particularly crucial - having it tattooed on his body. Given his handicap, Leonard is the last person who should be conducting an investigation, but that's just what he's doing: looking for the man who raped and killed his wife, and who took away his ability to make new memories.

Not content with the challenges raised by making a film about a character who has to work out where he is every time he wakes up, Nolan has complicated life further by telling the story backwards, cut up into narrative chunks that last as long as the character's memory - with extensive, but not obtrusive, use of first-person voice over. It all sounds like a recipe for high-concept pretension - but the narrative tension is maintained expertly throughout, and the end result is both gripping and intellectually satisfying.

There are even moments of black humour - as when Leonard finds himself running in a trailer park, and can't remember if he's chasing or being chased. The other guy fires a gun at him, and the penny drops.

Guy Pearce plays the title role with the right mixture of determination and fazed humility. The fact that the ending leaves too many questions unanswered will, if anything, only boost the film's word-of-mouth appeal; Memento is the sort of film that gives rise to long post-screening discussions. It should perform strongly on limited release in sophisticated, urban markets worldwide.

Nolan has said that this would be 'a great film to see on DVD' - because of the chance the new medium offers to rewind, review and check; or even to view the film in chronological order. Though he also makes it clear that Memento was not made with DVD in mind, his comment raises interesting issues of the extent to which the DVD outlet can be expected to affect film structure in the future.