Donmar director Michael Grandage is clearly fascinated by Argentina. Having directed Evita, he has now sanctioned a revival of Manuel Puig's play set in a Buenos Aires jail in 1976. But although Puig's fable started as a novel and has been turned into a movie and a musical, I fail to see its appeal, except as an opportunity for a virtuoso performance.
The action takes a long time to develop. It shows Valentin, a political prisoner, banged up with Molina, a gay window dresser. A naturally edgy relationship is alleviated by Molina's narrative gift, which largely consists of recounting the plot of a 40s panther-woman horror-movie. But Molina's instinctive tenderness gradually softens Valentin's hard heart, until sexual contact is finally achieved.
Obviously there is more to the story than that; but, frankly, not nearly enough. Valentin is a stereotype: a flinty political obsessive who reacts as if he's never seen a feminised homosexual before. There is also an implausibility in Valentin's failure to suspect Molina's supply of ever more succulent food-parcels. We know they are a product of Molina's reluctant recruitment as a spy upon his fellow prisoner, but you'd have thought a hard-nosed rebel might have got suspicious at being fed chicken legs and crystallised fruit.
If the play works at all, it is as an ironic love story: through his bond with Valentin, Molina is led into an act of unwitting betrayal. The evening's only other virtue is that it provides a showcase for the talent of Will Keen as Molina. Keen has a Guinness-like gift for stealthy transformation. Here he turns himself into someone doubly imprisoned: as a cell inmate and as a woman trapped inside a man's body. And he conveys Molina's inherent femininity with the subtlest of touches: the way he lightly holds a cup with little finger crooked, or by his emphasis on hard, climactic consonants. Keen neither flounces nor prances, but implies Molina's sexual duality through his graceful economy.
The gullible Valentin is a less rewarding role, but Rupert Evans lends it the right youthful ruggedness. And Charlotte Westenra's production conveys an atmosphere of claustrophobic oppression and boasts an imaginative sound score from John Leonard: at one point, as Molina relives the horror movie, we even hear the ominous, echoing tap of high heels on a deserted, night-time path. But, at the end of the day, Puig's play is an etiolated fable that celebrates a belated sexual awakening without shedding new light on life in a police state.
· Until May 26. Box office: 0870 060 6624.
