Film: The Big Picture - Hey sister, go sister

HILARY AND JACKIE (15) DIRECTOR: ANAND TUCKER STARRING: EMILY WATSON, RACHEL GRIFFITHS, DAVID MORRISSEY 121 MINS

At the age of eight she was considered a remarkable musician. Invited to play a solo for BBC radio, she agreed on condition that she could bring along her younger sister, who later got an earful from her mother for bursting a hole through a drum. The name of this brilliant soloist was Hilary du Pre, and she played the flute; the sister who disrupted the recording was called Jackie, and she played the cello.

By now we know which sister turned out to be the real prodigy, though why Jacqueline was favoured with greatness while Hilary failed her flute exams is a mystery that Hilary and Jackie doesn't try to unlock. There are scenes of Mrs du Pre (Celia Imrie) and Hilary eating sandwiches on a bench, waiting for Jackie to emerge from her lesson; but this is a shorthand for hard work, not genius. Film deals with genius by turning it into something else, such as eccentricity, or madness, or illness - all three of which figure prominently in the short life of Jacqueline du Pre.

Anand Tucker's film is not so much a biopic as the dual portrait of a strange and intense relationship. It has been adapted by Frank Cottrell Boyce from the recent memoir by Hilary and her brother, Piers du Pre, whose central revelation concerns the bizarre sexual menage which Jackie instigated with her sister and brother-in-law. Divided into two narratives, the first half of the film maps Hilary's dawning realisation that her life will be spent listening to people enquiring after "your marvellous sister". Indeed, it's more painful than that: it tells of a woman carving out a life in the shadow of another's fame, only to have that life usurped by the very same person. Hilary falls in love with an amiable young conductor, Kiffer Finzi (David Morrissey), marries him and withdraws to what she assumes will be a haven of calm in the country.

The turning-point, not to say the talking-point, of the film arrives when Jackie shows up unannounced and, following a jolly reunion around the hearth, asks Hilary for the loan of her husband. Hilary refuses, not unnaturally, but when Jackie bolts into the woods to tear off her clothes and howl like a loon, she relents and persuades Kiffer to help out in the guest bedroom. This is the defining moment of the du Pre sisters' story, yet the film-makers hold back from explaining why Hilary made such a sacrifice. Was it a masochistic kind of complaisance on her part, or rather a guilty acknowledgement of Jackie's fragile acquaintance with sanity?

Just as we're trying to decide - my money was on Jackie being a predatory, egomaniacal monster - the film switches focus and runs the story back through Jackie's perspective. What seemed a manipulative streak is gradually revealed as a chronic need to be loved. Cosseted by her parents till the age of 20, Jackie was packed off on a two-year European concert tour with a Davidoff cello and no idea of how to survive. What emerges poignantly is not just her inadequacy but a dreadful sense of loneliness, illustrated in a small domestic detail. In the first part of the film, the du Pre family receive a parcel from Jackie on tour in Russia, and tear it open excitedly: it turns out to be a bundle of dirty laundry she has sent home. Yet the outrage you might feel on the family's behalf softens into pity when Jackie receives the washed laundry with almost rapturous gratitude, hugging the clothes to her face to catch the scent of home.

For all their attempts at fairness, however, the film-makers can't help making Jackie seem conniving, snobbish and wholly incapable of taking pleasure in others' good fortune. When Hilary has her modest nuptials at the register office, for example, Jackie retaliates by marrying the pianist Daniel Barenboim (James Frain) with the maximum of fuss. She reacts to the news of her father's contracting Parkinson's disease in cold fury: he's trying to compete with her own crippling multiple sclerosis. Even in illness, her basic instinct was to upstage. It's to Emily Watson's credit that she makes Jackie's selfishness and vulnerability all of a piece; that look of frowning, almost agonised concentration as she bends to her cello is, paradoxically, the time she seems most at home. Watson will probably get the plaudits (and the awards) for her performance, though I found Rachel Griffiths' patient, fearful Hilary the more affecting of the two. The way she struggles to hide the hurt of Jackie's casual cruelty behind a smile has nuances that Watson's more hysterical interpretation can't match.

Absorbing as it is, Hilary and Jackie feels a confused and slightly prurient film. While it seeks to celebrate one woman's extraordinary gift, its focus is in fact the weird entanglements of her sex life. Neither is adequately elucidated. Tucker and his team apparently consulted Hilary du Pre prior to filming, which may explain why it is, ultimately, a work whose emphases are as conspicuous as its omissions.