"There used to be a me behind the mask, but I had it surgically removed." So spoke Peter Sellers - legendary comic, man of a thousand faces and, according to Stephen Hopkins' insightful biopic, a mum-fixated, wife-beating monster. Not even his children were safe. An early scene shows the comedian's young son accidentally scratch his father's new Jag. Peter's petulant response is to stomp, Godzilla-like, over his toys. Later, having propelled first wife Anne (Emily Watson) into another man's arms, he trashes their London flat and threatens to leap off the balcony. (Given his public lusting after Sophia Loren, it's a wonder she doesn't push him.)
Sellers is not the first biopic to equate genius on camera with mania off it. But where it differs from the norm is to use its subject's shape-shifting as a window into his turbulent soul. "I do not know who or what I am," the star once claimed, and the director takes him at his word: this Sellers is a hollow shell who only comes alive when wearing a mask.
It takes a chameleon to play a chameleon and Hopkins has one in Geoffrey Rush. There's something uncanny in the way he adopts Sellers' most famous roles, from bumbling Inspector Clouseau to Being There's simpleton gardener Chance. But there's more to it than that. In the film's most daring gambit, Rush also morphs into real-life figures, using their voices to justify his behaviour.
Having Peter drag up to mimic his possessive mother (Miriam Margoyles) or channel the inscrutable Stanley Kubrick (Stanley Tucci) is an ingenious way of conveying his lack of self. The downside is that it shortchanges the other actors. John Lithgow so vividly inhabits Blake Edwards that it feels foolhardy to shunt him off screen. And how come Sellers imagines himself as Anne, but not as second wife Britt Ekland?
The movie is on safer ground in its frame-for-frame recreations of Dr Strangelove, I'm All Right, Jack and other classics, while Charlize Theron perfectly captures Ekland's voluptuous exoticism. In the end, though, this is Rush's picture, his fearless portrayal bringing us as close as we're ever likely to get to an essentially unknowable talent.