Eddie Izzard's now a West End regular (and soon to go to Broadway with A Day in the Death of Joe Egg); the League of Gentlemen just closed in Art (and during the run of that show, Jack Dee, Frank Skinner and Sean Hughes were amongst the rotating casts to appear in it); and Dawn French is on the way in My Brilliant Divorce.

So comics-turned-stage actors are nothing new. But the joy and discovery of seeing Alan Davies in his straight stage debut in a mordantly, bleakly funny play called Auntie and Me is that he takes to the stage as naturally as his famous curly mop sits on his head.

A hit at the 2002 Edinburgh Fringe, Auntie and Me transfers to the West End still feeling freshly minted. Davies plays Kemp, a bank clerk who has no friends or libido. What he does have is a perverse sense of duty when it comes to an ageing aunt he's not seen for 30 years. This propels him to drop everything and travel 200 miles to visit her when he receives a letter from her saying she's dying.

The only problem is that, once he arrives, she stubbornly refuses to expire. Instead, she sits and whiles away the time propped up in her bed, knitting compulsively: "This knitting of yours," he enquires of her, "Is it a long-term project?" And as she puts some make-up on, he helpfully suggests, "Why don't you let the mortician do that?"

There are plenty of amusing ditties of this sort, but just when Morris Panych's play seems like it's going to consist entirely of variations of that one joke, it delves beneath its apparently slight surface to deliver something deeper and darker about the nature of loneliness and companionship, not to mention revelations about his deeply dysfunctional upbringing.

Anna Mackmin's production gets the tone of this just right, immeasurably helped by Andy Phillips' lighting that superbly signals the changing seasons and times of the day and night on Hayden Griffin's appropriately bleak bedroom setting.

And, in a virtually wordless role, Margaret Tyzack as the bed-bound aunt (replacing Marcia Warren who originated the role in Edinburgh) does some amazing reacting that could succeed in stealing the show were Davies not already so in command of it.

- Mark Shenton