First Night: You Will Meet A Tall Dark Stranger, Cannes Film Festival

Woody Allen prefaces his new film with lines from Macbeth about life being a tale told by an idiot "full of sound and fury, signifying nothing." It's as if he is issuing a disclaimer to those who accuse him of taking himself too seriously. You Will Meet A Dark Stranger deals with dark subjects – bereavement, adultery, ageing, creative jealousy – in a light, playful fashion. There is none of the portentousness that made Cassandra's Dream such an ordeal. This is a breezy, funny, well-acted film that moves at such a clip that you don't quite realise how bleak its themes often are. Whenever matters threaten to drag, the voice-over and jazzy music propel the story forward.

The film opens with Helena (Gemma Jones) consulting fortune teller Cristal (Pauline Collins). She has just been abandoned by Alfie (Anthony Hopkins), her husband of 40 years, who has had his "teeth whitened and his skin darkened" and is on the prowl for a younger woman. Their daughter, Sally (Naomi Watts), is married to Roy (Josh Brolin), a struggling and increasingly embittered novelist who once showed promise. Other characters include an ultra-smooth gallery owner (Antonio Banderas), a young artist (Anna Friel) and a gold-digging ex-prostitute, Charmaine (Lucy Punch). There is a hint of La Ronde about a plot in which almost every character starts a new relationship.

Allen's vision of Britain is quaint and eccentric. You Will Meet A Tall Dark Stranger offers a tourist's eye view of London with parks, black cabs and quaint old bookshops to the fore. Allen is not especially alert to the nuances of the British class system and some of the dialogue here is tin-eared. However, this new film offers the familiar reassurances of Allen's New York-set movies: clever plotting, great gags allied with vivid characterisation. Allen could easily have taken the same material and made a downbeat drama about dysfunctional families in the vein of Bergman or Mike Leigh. Instead, in even the most excruciating scenes (a husband discovering his young wife in flagrante with a gym instructor, a woman telling her husband-to-be that the wedding is off), the comedy is in the foreground.

Jones here plays an English, home counties version of the Jewish matriarch in several of Allen's US movies. She is both funny and poignant: a lonely, betrayed old woman who looks to sherry and fortune telling to give meaning to her desperate life. Her scenes with Collins's medium play like something out of a British TV sitcom but are none the worse for that.

Hopkins's roué, Alfie, likewise combines humour and pathos. Given his own experiences at the hands of the media, Allen offers a surprisingly barbed portrayal of an old man in thrall to a much younger woman. Alfie is an absurd figure, working out in the gym, popping Viagra pills and behaving as if he is a young buck about town.

Brolin, generally to be found playing action-heroes, is cast as the introspective and neurotic novelist who has lost his confidence. He conveys, effectively enough, his character's self-pity and his arrogance as he tries to cope with professional disappointment by hitting on his beautiful neighbour (Freida Pinto.) Naomi Watts is impressive as the harassed and depressed young wife who develops a crush on her boss (an engaging cameo from Banderas.) Allen's portrayal of Charmaine, the pea-brained working-class vamp, verges on caricature. Lucy Punch is funny but strident as the one character in the film with no emotional depth whatsoever.

You Will Meet A Dark Stranger benefits from its wry, detached storytelling. Allen doesn't judge his characters, however shabbily they behave. Nor does he provide a glib finale, resolving everything. The storytelling is deliberately open-ended: he is not trying to solve the characters' problems but simply to state those problems correctly.