In his published diary (available in a neat Faber edition with the shooting script), debutante feature-maker Darren Aronofsky explains that he favours short films. It's just as well if his - literally - dizzying debut is anything go by. So paranoid is its story, so urgent its camerawork and so high-contrast its photography that much more Pi and it would likely induce a mass migraine in even the most receptive audience. It marks a remarkable synthesis of style and subject.

Sean Gullette is the brilliant but disturbed young mathematician Max Cohen. His tiny, ant-infested New York apartment is a mess, given over to the self-build super-computer Euclid that Max is convinced can isolate the pattern he knows lurks within the Stock Market. What he gets is an apparently meaningless 216-digit number. But not meaningless to Marcy Dawson (Pamela Hart), the representative of a sinister Wall Street cabal intent on abusing Max's work to her own nefarious ends. Or Lennie Meyer (Ben Shenkman), an Hasidic Jew who demonstrates Kabbalah number theory and convinces Max that his magic number is in fact the true name of God. Eventually his dabblings destroy Euclid and Max is gifted a "not-yet-declassified" mega-chip by Dawson. Pursued by the money-men and Meyer's sect, Max is forced to drastic ends.

Part William Gibson techno-fever, part Kafka nightmare, part Philip K. Dick paranoia. While it's a largely lazy critical trope to refer to anything in relation to David Lynch, there is something of Eraserhead about Pi. Visually the film lives inside someone's head, thus its images are as diffuse and stuttering as only the decaying mind understands. And like the Lynch, this writer-director demonstrates a sure grasp of his material even at the risk of alienating viewers. There is very little calm within the film as Max is assailed both by debilitating headaches and the need to decode mathematics in everything he sees - in the leaves on a tree, the curls of cigarette smoke, milk swirls in his coffee. Faith in chaos.

The soundtrack, smartly, offers little by way of respite from the digital assault, augmenting Clint (Pop Will Eat Itself) Mansell's fidgety electronics with the moodier, more outré filmic end of Orbital, Autechure, the Aphex Twin and Massive Attack (the spooky, building 'Angel').

This intoxicating digital horror works because it's never still long enough to explain its occult sensibilities. It is in love with the quasi-mystical truths of mathematical symbols themselves rather than mathematics per se. We want to believe that that very sexy gauze of notation, geometrics and numbers and we see churning beneath the titles is Truth.

It is at once refreshingly bold in its embracing of new ideas and oddly nostalgic in design, assimilating the likes of Cronenberg (Scanners and Videodrome in particular) and Tsukamoto (Tetsuo) along the way. But despite its borrowings - and the fact that at times it feels rather like sitting a maths exam after revising all night on black coffee and Techno - you won't have ever seen anything quite like it before.