With its nondescript, brainiac anti-heroes and dialogue crammed with technospeak, Primer is the ultimate geek movie. Viewers and critics fall mainly into two camps: those who don't understand it and think it's terrific, and those who don't understand it and think it's rubbish. I tend to agree with the latter group, except I think it's very clever rubbish.

Written, directed, edited, scored and shot virtually single handedly by ex-math student and software engineer Shane Carruth, Primer concerns a couple of nerdy engineers, Aaron (Carruth) and Abe (David Sullivan), who accidentally invent a time machine while tinkering in their suburban garage. With believable self-interest, they initially use it to peek at future stock market activity, but when they realise that the machine is generating uncontrollable doubles of themselves, the dangers and ethical implications become clear and their friendship begins to deteriorate.

Unstable, incomprehensible and as alien as Eraserhead, Primer's jargon-heavy screenplay wants us to collaborate in its resolution. If we have to work through the gobbledygook to figure it out, we're already invested in the movie - we want it to mean something.

Really, it's all just nonsense, but Carruth gets enough right - the atmosphere of paranoia and inchoate dread, the buzzing, fluorescent-lit locations, the enormous, otherworldly Xerox machine at its center - that the film almost works. Armed with only two weeks of film school, Carruth has made a movie that's essentially about the dangers of being too smart.

Unfortunately, Primer stands as an example of its own thesis.