It begins with a blank screen, dripping sounds - water maybe falling in a cistern. Then we move to scenes of rain or sleet falling in a brick lane. You could sit and watch this for two hours, and leave out all that nymphomania stuff, while you're at it. We are grand and snug here watching the rain falling in the bleak, labyrinthine alleyway.

But the situation must be faced, and it will be disturbing and upsetting, because it is von Trier after all. Cue loud metal band, and the camera cuts to a woman lying in the lane. An elderly man named Seligman (Stellan Skarsgård) comes to her aid and brings her back to his tiny, dingy flat. She lies in his bed; he brings her a cup of tea. Seligman asks this woman called Joe (Charlotte Gainsbourg) to tell him how she descended into such a state.   

She insists she has been a bad person, but he tells her that he believes there is no such thing as a sin. He fails to understand how she can reject religion, and yet feel terrible guilt about her life to date. Nothing is certain; nothing set in stone. On the wall of the man's flat there is an icon of the Madonna and child, even though Seligman too has rejected religion.

Joe begins to tell her lengthy tale of addiction to sex, mostly with men - 10 a night sometimes. Her story unfolds in a 1970s scenario, complete with period detail: the menial office job, the telex, the desk-phones. We have a sense of Bridget Jones circa 1973, but with more disturbing hormonal antics. Stacy Martin plays the younger Joe.

Even though there are sexual encounters, the first 'volume' is not in essence about sex, the same way as The Master is not about a cult per se. Sexuality is, rather, the peg to hang the garment on, as a cult movement is the peg in the Paul Thomas Anderson film.

If the first 'volume' is about sex, then it is also about sex and death. Joe's tender relationship with her father - a medical doctor with his own demons of instability - is deeply moving. And Uma Thurman delivers a brilliant cameo as a spurned wife.

But volume two is a terrible let-down, as the film runs the entire gamut of nasty violence and unsettling perversion. Also, like Ingmar Bergman at his weaker moments, von Trier is putting unwieldy, analytical stuff into movies that just does not fit well within the dramatic requirements. It's like telling instead of showing.

It's a confrontational Scandinavian approach that would no doubt see the Danish director defend the business of turning up stones to see what creeps out, for the sake of catharsis. But it just doesn't work, and he loses complete focus in tawdry sensationalism. It is a pretty spectacular failure and nihilistic in the extreme.

Nymph()maniac: Volumes I & II are released at the IFI and selected cinemas. Volume I is 118 minutes, volume II is 123 minutes. Normal ticket prices are applicable to each.

Paddy Kehoe