As You Desire Me, Playhouse, London

Scott Thomas is first encountered as the amnesiac Elma, a cabaret singer in a sleazy Berlin nightclub 10 years after the First World War. The actress is brilliant at letting one see how this louche identity is the improvisation of a woman left to the mercy of the market. So she's intrigued and disturbed when a man appears to tell her that she is, in fact, Lucia, an Italian aristocrat's wife, missing since she was gang-raped and abducted by invading soldiers.

Reclaimed like a piece of unlabelled left-luggage, she leaves her possessive lover Salter (a growling, George Grosz-like figure in Bob Hoskins' not very convincing performance) and goes to Italy. But her new existence is beset with problems. It emerges that the husband Bruno (Richard Lintern) has a vested interest in endorsing her authenticity because his wife's dowry is otherwise about to pass to her sister. Determined to prove that she's a fake, Salter arrives from Berlin with a ravaged madwoman tracked down in an asylum who has claims to be Lucia. The criteria for verification are indeed treacherous. As the Scott Thomas character concedes, the real wife would surely be unrecognisable after her ordeal. The fact that she herself was identified ironically counts as evidence against her.

This may all sound rather abstract, but Pirandello's gift is for (as he put it) "converting intellect into passion". In her extraordinarily accomplished, witty, moving performance, Scott Thomas, with her bony beauty and nervy aplomb, shows you a woman who longs for a fresh start.

Presenting a play permeated by doubt, Kent's opulently designed production is, without question, the genuine article.