Welcome to the mind of Max Cohen (Guillette), a maths prodigy who locks himself into a tiny New York apartment with a homemade supercomputer, conducting an intense study of momentous numbers and suffering headaches that seem to be the side effect of his genius.
When a strange numeric pattern thrown up by the fluctuations of the stock market, which only he can see, drives him even further into number-madness, Max is pursued by sinister Wall Street manipulators who believe he can predict the financial future, and a group of Hassidic researchers who think he has hit upon the lost name of God.
This New York indie combines something of the look and ambition of Abel Ferrara's The Addiction with the weird scientific rigour of early David Cronenberg. Even more hung up on its numbers than the similarly calculator-happy Cube, the film fully represents Max's world-view, to the point when the audience can't fail to notice how many grids and spirals have been worked into the plot: a Go board, the New York subway system, the exposed whorls of a human brain, computer chips, the Hebrew language, scribbled notes, even the Milky Way. Naturally, given the famously non-recurring nature of the title number, no answer can possibly be forthcoming and you get kicked rudely out of Max's skull - during a hideous bit of DIY Black and Decker surgery - before it all starts to make sense.
Writer-director Aronofsky suggests vast conspiracies just beyond comprehension, but limits the film to the viewpoint of the mad and maddening Max. It can't fail to be absorbing, but it also inevitably disappoints as the big breakthrough the script has been teasing us with is withheld in favour of a chilling 'happy' ending.
Shot in grainy, high-contrast black-and-white with a lot of simple but effective optical and aural tricks to suggest the workings of Max's unusual mind, this is one of the most intimate movies in recent memory.