Who's the weirdest of them all?

Drug paranoia rules in a dark and gripping thriller

<strong>A Scanner Darkly (15)</strong> dir: Ri

The twisted science fiction of Philip K Dick has provided rich pickings for cinema: Blade Runner (1982), Total Recall (1990) and Minority Report (2002) were all adapted from his work. But no film has captured the writer's sense of dread as acutely as A Scanner Darkly. It would ordinarily be an insult to say that a film is cartoonish, but that's what this is - visually though not morally. After it was shot and edited, the picture was handed to a team of animators, who spent another 15 months painting over the live-action images in a process known as "rotoscoping". You might say the end result is animation underpinned by reality, or reality enhanced by animation. Or you could just cut to the chase and call it freaky.

The film is set in Orange County, though anyone expecting The OC is in for a nasty surprise. It takes place seven years from now, when 20 per cent of America's population is addicted to the hallucinogenic Substance D. Bob Arctor (Keanu Reeves) is an undercover cop known as "Fred", his identity so closely guarded that his own superiors don't know what he looks or sounds like. Bob is assigned to spy on his circle of friends, including Donna (Winona Ryder), whose addiction has made her averse to physical contact.

In the first of several brain-mangling twists, Bob must also spy on himself. Kitted out in his "scramble suit", a full-body outfit that causes the wearer's entire physical appearance to alter several times per second, Bob presides over surveillance tapes of his own life. I'm not sure what the protocol is if you suspect you've been engaged in illegal activity. Do you grass yourself up? And if you discover you've informed, do you try to intimidate yourself - "I know where you live", that sort of thing? Sensitive viewers would be forgiven for suspecting that their jumbo cola had been spiked with Substance D.

Our introduction to the drug's side effects comes in the squirm-inducing opening scene, when the twitchy Freck (Rory Cochrane) finds bugs scurrying all over his body. He captures a few of the blighters in a jar, screws on the lid and heads off to show his friend Barris (Robert Downey, Jr). When he arrives, the jar is empty. Later, another addict watches dumbfounded as his housemates metamorphose into giant cockroaches mid-conversation. Clearly mindful of etiquette, he carries on as though nothing has happened, as opposed to setting about them with the heel of his shoe or a can of Raid.

If A Scanner Darkly had been any conventional film, such deranged moments would have stood out. But the rotoscope animation lends every shot the same texture. A creature whose engorged head is festooned with blinking eyes looks strangely humdrum, while a conference at which Bob delivers an anti-drugs lecture feels bizarre in its stilted normality. The writer-director Richard Linklater has used rotoscoping before, in Waking Life, his 2001 meditation on the nature of dreams. Harnessed to a suspenseful narrative, the technique seems less fanciful than in the earlier film. The wobbly lines and shifting skin tones reinforce the impression of a world where divisions between reality and fantasy, police and criminals, have been gently eroded.

The benefits of rotoscoping for the actors are vast. It makes a refreshing change to see Reeves and Ryder looking animated - in both senses of the word. And far from being smothered by the animation, performers such as Downey and Woody Harrelson seem more their strung-out selves than ever. They achieve an almost operatic mania in the scene in which they contemplate selling their house because they believe the police have planted drugs in it; their paranoia is not so overwhelming that it stops them wondering if they should mention the stash to help the sale. Including Radiohead songs on the soundtrack threatens to overstuff the joint, or whatever the druggy equivalent is of gilding the lily. But in all other respects A Scanner Darkly is a riveting and well-judged thriller: it's a modern Naked Lunch, but it's no picnic.

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