Watching Robin Williams, you can't help but imagine that somewhere under his jacket is a big switch that throws between his two performing selves.
Firstly, there's Williams the funny man, who can be anything from a motormouthed maniac (Good Morning, Vietnam) to a sentimental missionary for the healing power of laughter in general (Patch Adams).
We have seen a lot of that funny self gone soft in recent years, mostly in films so horribly syrupy that they constitute a genre in their own right (Jack, Fathers' Day, Patch Adams and Bicentennial Man).
Then there's Williams's second screen self: an odious creep who speaks rather too softly, smiles without showing any teeth and probably leaves a trail of slime if he shakes your hand. He is usually a villain.
Seeing Mrs Doubtfire play the bad guy in three 2002 films--Insomnia, One Hour Photo and Death to Smoochy--shocked a few critics to the point that many hailed the performances as tantamount to a career change.
His latest role as a repressed social misfit appears in The Final Cut, a shot at genre sci-fi by first-time feature writer-director Omar Naim. But Williams doesn't play a villain. The story is set in a dystopian future, where most people have chips in their brains that record their memories as films. These are edited as memorials once they are dead so that they can be safely played at their funerals.
Alan Hakman, Williams's character, is the best of these editors. He has a girlfriend (Mira Sorvino), but he is most comfortable alone with his editing suite, meticulously piecing lives together and posthumously absolving the dead of their sins. But he cannot absolve himself; he is haunted by the memory of daring a boy to walk a plank over a well, with fatal results.
Williams says solitary activity "is very comfortable for me. The isolation is part of being a comic. You are kind of an observer and then you perform." However, as soon becomes clear in an interview, Williams performs all the time.
He can barely finish a sentence in his normal voice.
Unless he's being funny as hell, the hyper-articulate torrent of words dries up and he starts bumbling and mumbling, to the point where parts of the interview transcript make little sense.
It's little wonder that his string of dark roles has run in tandem with his return to stand-up.
Stand-up has always been his refuge. Williams found fame as a visiting alien in the television sitcom Mork & Mindy in the late '70s/early '80s, but stand-up was his "survival mechanism" through the subsequent dark time--"the only thing that really kept me going, because you could talk about it, make fun of it and still make money from it".
"It gives you a kind of fearlessness, because you know that to go out and do it you have to be ready to put your arse on the line.
"Directors say they like working with comics, usually because they're not afraid to try stuff. They have to [be prepared to] do anything to get the laugh. They are shameless on that level, but also fearless."
He says he would like the zany Robin Williams on film again, but those roles do not seem to come along any more.
"It's hard to find a script where you can kick out that hard, and if you do people say: [puts on a very proper, affected voice] 'That's not the role, you know.'"
Williams says these days it is only animated movies where he is given leeway to let rip. This year he voiced five characters in George Miller's Happy Feet, an animated film about penguins due out in 2006.
He loved Miller because he let him go crazy with it.
It isn't true to say Williams is no longer offered comedies--but they are sometimes bizarrely inappropriate. He says he received a script after One Hour Photo for a new Pink Panther film about Inspector Clouseau's youth: "I went, 'Uh, I'm 50.'"
The death of close friend Christopher Reeve has only increased his awareness of his mortality. The 53-year-old has no intention of becoming an old fool who thinks he can romance teenagers on screen through sagging jowls.
Short and vaguely simian, he was never quite leading-man material as anything but a joker; his Oscar-nominated role in Dead Poets Society was a shining, if typically mawkish, exception.
There is a kind of liberty, he says, in swimming in the murkier waters of The Final Cut after years of generating sticky sunshine.
Such films are not necessarily successful. Variety criticised the script's inability to tie together narrative threads such as the love story and the political intrigue. It also pointed out the lack of on-screen sexual chemistry between Williams and Sorvino.
But I liked Williams for choosing to make The Final Cut. Yet I suspect we will see him in a few more glutinous family comedies before he finally hangs up his red nose.