One of the most pitiless theatre experiences in recent years -- try thinking of a Jacobean revenge tragedy, produced with music on Broadway without even one softening moment - has come at last to the screen in Tim Burton's film of "Sweeney Todd: The Demon Barber of Fleet Street," - and as you know it's adapted from a Stephen Sondheim musical, yet. "Sweeney Todd" was originally a loose collection of stories about such a man in 19th century London, now written for the screen from Sondheim's musical by John Logan, and it is as powerful a film as I can recall seeing.

It's the story of a barber with a beautiful wife and child, who come under the eye of a corrupt London judge, Judge Turpin (Alan Rickman), who trumps up a charge against the barber and sends him to Australia, then destroys the wife and takes the child as his ward and prisoner, with the intention of marrying her when she comes of age. The barber escapes, changes his name to Sweeney Todd (Johnny Depp, of course), comes back to his old place of business, still run by the widow Mrs. Lovett (Helena Bonham Carter), who makes "the worst meat pies in London," and sets up shop upstairs to plan his revenge.

This is a London that's dark, lit as only Tim Burton can light his films, creating an atmosphere so thick the sun never shines on it. And once again his protagonist is Johnny Depp, who ever since "Edward Scissorhands" has found a partner in Burton.

And his revenge is wonderfully appropriate: he cuts the throats of his customers, sends them down a chute to Mrs. Lovett's sausage making room, from where she now serves "the best meat pies in London."

What is so marvelous about all this is that there is no quarter given - by anyone or any element of the film; the performances are merciless, single-minded, apt in every way to the story. Johnny Depp plays against his own boyish looks and charm to become a completely sympathetic villain, singing Sondheim's brilliant songs without even a moment that would distance himself from his character; I think that in a year with wonderful performances from many actors, this is the best I have seen. And Helena Bonham Carter as Mrs. Lovett, with dreams of her own to retire with Todd, is the perfect foil; much younger than Angela Lansbury, who played this in the original Broadway production, she is no less steely in her actions. And Alan Rickman as the judge, together with his foil, the beadle Timothy Spall, might have stepped out of a real Jacobean tragedy to play their roles here. And you've no doubt heard of Sacha Baron Cohen as the Italian barber Pirelli whom Sweeney defeats in a curb-side shaving match.

All of these have their day, but when "Sweeney Todd" is over, you think back on Johnny Depp's performance as one of the great moments in film history. It is not to be missed.