THEATRE All Things Considered: Hampstead Theatre

The hero of Simon Gray's 1975 play, Otherwise Engaged, has just bought a new recording of Parsifal but is prevented from sitting down and listening to it by a string of unwanted visitors. The same comic pattern - fastidious man, who wants to shut out the world, repeatedly foiled by irksome interruptions and claims on his sympathy - underlies All Things Considered, a new play by 27-year-old Ben Brown. Except that his protagonist has a more drastic end in mind than a solitary wallowing in Wagner.

Brown's remarkably assured, if old-fashioned-seeming comedy, was inspired by the case of an American professor of applied ethics who, believing that a human being has the right to decide how and when his life should end, put his theories into practice by committing suicide. At the start of Brown's play, set in a flat in an Oxbridge college, we see philosopher David Freeman (Christopher Godwin) attempting to take this tidy-minded, rational exit from an existence that no longer interests him.

His book, Matters of Life and Death, has just been published; he has recently buried his beloved mother. A childless divorcee pushing 50, he draws the curtains, pours the whisky, counts out the pills, and dons the plastic bag. Then he gets an urgent message from a friend on his answering machine, the start of a series of messy obstacles to his cerebrally neat intended self-slaughter.

Prettily choreographed in Alan Strachan's enjoyable production, the overlapping intruders include an electrician who has come to do some urgent rewiring; a voluble and voluptuous Berkeley academic (Holly Hayes) who sees death mainly from a utilitarian "recycling of organs" angle; a randy colleague (Michael Lumsden) who has still to learn that bedding and impregnating undergraduates is no longer a perk of the job; Timothy Kightley amusingly officious college chaplain; and excellent Susie Blake as the lovelorn librarian whom David took off the shelf for one night and then promptly put back.

In Alan Ayckbourn's Absurd Person Singular, there's a running joke about a woman in suicidal despair whose efforts to top herself are serenely misinterpreted as mundane household accidents by those around her. All Things Considered, by contrast, has a hero who maintains that he is level- headedly not in despair and who is upfront about his aims. How far this philosophical calm is or isn't a facade never becomes a satisfactory dramatised question, though. Nor do you get the sense, as you do in Otherwise Engaged, that the hero's detachment has become, in itself, a kind of slow-puncture suicide.

The play is not without irritating implausibilities. As David is about to take the pills at the start, a friend and colleague whom he sees every day leaves a message that begins: "Hi, David, how's life? What a stupid thing to say..." It's not the only contrived irony that comes courtesy of David's answering machine. But if the tone of the last few minutes veers into queasy-making heartlessness, much of the play is very funny - in particular, the scene where a flattered David thinks he's being interviewed about his newly published philosophical opus ("so there are quality papers after all!") only to discover that the glamorous, drop-dead-cynical Guardian journalist (lethally captured by Jane Slavin) is there to talk about his famous ex-wife's viciously tell-tale autobiography.

Brown, whose influences all seem to be at least twice his age, is clearly a talent to watch. Will he turn out to be more than a paler shade of Simon Gray? To 5 July. Booking: 0171-722 9301.