Eyre's film of John Bayley's bestselling memoirs has the virtues one imagines Iris Murdoch would have hoped for: it's an intelligent, literate film with a sure sense of its world and honest, moving performances. If it's also underwhelming, perhaps these virtues can become vices: it's overly literal, solipsistic and even a little academic. For the benefit of those dozing at the back, Murdoch was a very fine British novelist and philosopher. Educated at Oxford in the 1950s, she fashioned herself as a free spirit - yet oddly, when the stammering John Bayley paid court, she chose him to be her husband, and they lived together until her death in 1999. Eyre's film switches between the couple's courtship and the painful last years when Murdoch suffered from Alzheimer's disease, often eliding four decades in a single, eloquent pan. The twin casts are perfectly matched: Dench and Winslet as the flinty, hay-haired Iris; and Broadbent and Bonneville as John, almost a caricature of the absent-minded don, the cuckold happy with his nest. She sees decency in him, an intellect to parry, and an unworldliness which obviously suited her purposes. Eyre is interested in how dependency shifts between them, in what keeps a couple together even in the face of Alzheimer's - and in watching a brilliant mind regress. Yet, perhaps inevitably, the film becomes less interesting as it goes on.