NOTE: The following review dates from January 2005 and this production's premiere at London's Hampstead Theatre, ahead of its West End transfer to Trafalgar Studios. For current cast and tour venue information, see performance listings.

Suddenly, from out of nowhere, we seem to have a new voice – Simon Mendes da Costa and a product of, well, actually it's hard to say except perhaps the school of life.

Initially a civil engineer, followed by various changes of heart, da Costa ended up writing for Hampstead's youth theatre group. Losing Louis is his second full length play - his first, Table for One, at Islington's tiny fringe venue, the Hen and Chickens, earned him a Time Out's Critics Choice. So he has, as they say, a bit of `previous'. But I'll eat my hat if Hampstead don't actually secure a West End transfer with this one.

For one thing, da Costa has emotional maturity and insight well beyond such brief dramatic experience. Okay, so it may not be the most original play you'll ever see. And in the way da Costa plays with time, death, sibling rivalries, humour and pathos, there's bound to be comparisons made with Alan Ayckbourn.

What gives Losing Louis its own special flavour however is its very modern, sexual cheekiness and the way da Costa weaves themes and time spans - we slip between the '50s and now, in a trice - around one event, witnessed by us right at the very beginning of the play. As a six-year-old, David Horovitch's Tony inadvertently witnesses his father, Louis, in full flagrante with his mother's best friend and house-nanny, Bella. The ramifications of that event and the truth of how such childhood legacies leak into adulthood is what, in my opinion, gives Losing Louis its irresistible force and dramatic weight. That and a cast and production by Robin Lefevre that you couldn't hope to see bettered.

Like Ayckbourn, da Costa builds his comedy on character and situation. When Lynda Bellingham's chic-suited (and surprisingly sexually imaginative) Elizabeth tells us Louis died in the next door bed, we laugh because Alison Steadman's wonderfully blousey, Sheila has just told us she has moved there precisely to avoid sleeping in the bed she thinks her ex father-in-law died in. So, too, in a myriad other ways – Sheila's desire for the family clock, the undiscovered will, undertakers doubling as cake makers - a steady stream of laughter-lines erupt based on the all too recognisable human traits of greed, snobbery and distress around death and dying.

Add in its sexual openness and da Costa's interesting take on Jewish/Christian identity – there is a marvellously funny, poignant exchange between Horovitch and his brother Reggie (the excellent Brian Protheroe) about relative personal attributes – and Losing Louis, for my money, has the lot. I laughed, I cried. What more could you ask for?

- Carole Woddis