The premise for Eternal Sunshine of the Spotless Mind is a simple one: imagine if there were a scientific procedure that could remove your memories of specific people. Clementine (Kate Winslet) decides to undergo this process to remove her memories of Joel (Jim Carrey), with whom she has just painfully broken up.

Joel, on finding out that he's been deleted, seeks revenge, and arranges for the same clinic to delete his memories of Clementine. `Is there any risk of brain damage?', he asks. The doctor (Tom Wilkinson) replies, `Well, technically, the process is brain damage.'

The treatment begins, and as they are deleted, we watch Joel's memories of the relationship in reverse, from the painful break-up back to happier times. However, Joel is not quite unconscious while this is happening, so the scenes have a unique dream-like quality, as Joel comments on what is happening, and uses his imagination to change details.

Gradually, he realises that the good memories of Clementine outweigh the bad, but he can't stop the procedure, so instead he tries to defeat it by hiding memories of her, dragging her out of scenes and inserting her into deeply repressed, unrelated memories; such as when his mother discovered her son's mind wasn't quite spotless.

It sounds confusing, and it is at first, but the chronology seems quite clear once you grasp the film's logic. The screenplay is another triumph from Charlie Kaufman (Being John Malkovich, Adaptation), displaying all the craft and ingenuity of his previous work, but with a new level of emotional depth.

Despite all the twists and turns, the film is primarily a love story, and it centres on the double-edged nature of attraction. Joel and Clementine are drawn together because he is introverted and she is wild, yet over time these qualities lose their charm, and they find each other boring and needy respectively. In the end, the film asks: are the good times worth the bitter fallout?

Director Michel Gondry deserves all the plaudits he will receive, both for the magical realist cinematography, and the wonderfully low-key ensemble in which Carrey and Winslet shine. Eternal Sunshine is a rare treat, a film whose visual and narrative flair seem to redefine the possibilities of the medium, but which nonetheless rigidly focuses on storytelling and character.

(Released by Focus Features and rated "R" for language, some drug and sexual content.)