The Belgian playwright Arne Sierens is a former punk singer - so you would have thought this short two-hander might muster some swagger and attitude. But though it references sex, drugs and rock'n'roll, it feels inert and irritatingly inconsequential. Briskly translated from the Flemish by Stephen Greenhorn and comprising a series of conversations between the ex-girlfriend of a drummer and his less successful musician half-brother, it promises spicy revelations that never actually arrive. And though Sierens makes some valid observations about the mutability of memory and the way in which our realities are shaped by conflicting perceptions, he never persuades us to care about either of the two combatants squabbling over different versions of the past.

Once the rock-chick moll to the volatile Serge, Paola is now the divorced mother of a truculent son. On condition that his school work improves, she arranges drumming lessons for the boy and is startled to discover, when Raymond, the teacher, turns up, that he is part of her turbulent former life. While she remembers Serge as a musical genius manqué and their affair as a grand passion, Raymond insists that she made Serge miserable and the band was a failure - and that their lack of success was partly Paola's fault. Fragments of personal history are swapped back and forth, each time with variations, like a recurring musical motif. Old resentments and new disappointments seep through the surface of their uneasy business arrangement that looks increasingly like a kind of sado-masochistic psychological prostitution.

It's no surprise to learn that Paola's unhappy marriage couldn't compare to the extremity of feeling she had for Serge; nor that Raymond has never managed to creep out from under the shadow of his charismatic brother. Nadia Latif's efficient but under-powered production fails to lend weight to the pair's bickering, and though Holly Atkins as Paola and Anthony Shuster as Raymond are perfectly competent, they are straitjacketed by the slight material.

Box office: 020-7503 1646. To Dec 20

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