YET another well-meaning European liberal - one whose student days were, perhaps, taken up with demanding an end to apartheid - has set out for Africa to tell us a story of the white man's burden.

This time round its Bille August, director of Pelle the Conqueror, and his subject is the relationship between Nelson Mandela and one of his jailers. Since this decent, worthy film went into production, there has been a steady swelling of gossip to the effect that James Gregory, the Robben Island warder who worked with Mandela for close to 30 years, greatly exaggerated the friendship between himself and the ANC leader. This, perhaps, explains why August has chosen to focus on Gregory's story and has allowed Mandela to sink into the background somewhat.

Dennis Haysbert, best known as the President in 24, ends up with precious little to do. Consistently mellow and even-tempered, his dignified Mandela, whose snippets of sage advice help turn Gregory from racism, comes across like a bigger, bolder, less green Yoda. This is the jailer's story, not the revolutionary's.

Still, for all the film's compromises, it remains a surprisingly touching piece of work. Joseph Fiennes, playing an ordinary man, selected to spy on Mandela because he knows the Xhosa language, does a good job of telegraphing the internal shifts and conflicts that edge him towards an understanding of the injustices visited upon the black majority. As his (let's say fictional) character begins to warm to the captive and allows him favours, the picture takes on the quality of a less sophisticated, but still involving, cousin of The Lives of Others.

Mention should also be made of the skilful art design and location work, which effectively conveys the odd collision of African exoticism and painfully drab conformity that characterised the white bits of this odd country in its grim years. It looks like contemporaneous Portadown, but with better weather.