Theatre Giovanni's Room Drill Hall, London

There are two basic reasons for wanting to stage a classic - either because it has some universal message, or because it's an interesting period piece. You guess that Out and Proud's adaptation of James Baldwin's 1956 novel Giovanni's Room is predicated on the first one - a note in the programme by the director, Maia Guest, talks about "Baldwin's timeless prose" - but what you notice is just how old-fashioned it now seems.

The story follows the descent into hell of David, a young American living in Paris, who enjoys an affair with the beautiful waiter Giovanni but ruins both their lives when he deserts Giovanni for a more conventional relationship with an American girl.

On the surface, this is a straightforward fable about the folly of trying to deny your true self, and certainly that aspect of the story hasn't lost its relevance. More interestingly, it's an old-style drama of the clash of Old and New worlds - we're deep in Henry James territory here, with American puritanism, which sees everything in black and white, failing to come to grips with European pragmatism.

At their first meeting, Giovanni talks to David about pain and death and love, "All the things you Americans do not believe." And later on, when David's fiancee Hella (played by Guest) catches him in flagrante with a sailor - after some embarrassingly archaic lines about how a woman needs a man before she can be herself - she declares "Americans should never come to Europe" (a line that on Wednesday got the biggest laugh of the evening): it makes them unhappy - "and what's the use of an unhappy American?" Giovanni can't understand why David should feel unable to carry on an affair with him at the same time as seeing Hella, his fiancee.

This isn't simply a difference of opinion about morality; it's about the whole question of how we construct our identities. The problem for David is not simply that he is a gay man struggling to be hetero; it's that he feels he needs to define himself as being one thing or the other, and then act in accordance with his decision. For Giovanni, the choice is between different actions; and what you are is defined by what you do.

That this complexity comes through intact is to the credit of Guest and her cast. Peter Gaitens is a sterling David, Ed Vassallo mostly a persuasive Giovanni (though the closing scenes, when he has to mime out solo his final murderous encounter with the decadent Guillaume, leave him exposed). They are brilliantly supported by Michael Roberts, nicely understated as the ageing, self-disgusted Jacques, and Bette Bourne's flamboyant Guillaume.

The adaptation starts slowly, with a long, wordy monologue by David, occasionally interrupted by other characters, and ends limply - the murder scene is unfortunately starchy. In between, though, the production manages to combine narrative flow with a sense of novelistic density and depth; so that, while it isn't timeless, at least time doesn't stand still.

n To 3 August at the Drill Hall, London WC2 (0171-637 8270)