Theatre: Gabriel Soho Theatre, London

At the climax of Gabriel, a man lies bleeding to death amid rising panic. He turns for help but, receiving none, cries: "This bitch would watch me die!" The doughty housekeeper with a heart of gold scolds, "There's a child! Watch your language!" Not a line you hear much nowadays and given that we're dealing with murder, I would say that swearing was fairly low down on the list of the characters' priorities.

The most startling thing about Moira Buffini's play is that it was written last year. If someone had told me this was a 1950s drama by Daphne du Maurier, I would not have been in the least surprised. In occupied Guernsey in 1943, the Becquet family have been forced to move into an old farmhouse, their grand home having been requisitioned by German officers. Head of the family is Jeanne, whose husband is dead, whose pilot son Myles is missing in action and whose Jewish daughter-in-law, Lily, gets on her nerves. She is also struggling to control her over-imaginative 10-year- old Estelle (Gemma Eglinton). Jeanne steers a high-risk course between collaboration and resistance. Having had one affair with a German officer, she is on the brink of toying with another when Lily throws the entire household into jeopardy by saving the life of an unknown, handsome young man who has lost his memory. Fluent in English, and, more worryingly, German, whose side is he on?

Buffini takes this situation, pregnant with possibility, and spins more plot out of it than you can shake a fistful of sticks at, with the result that the two and a half hours glide by, the dramatic tension cranked up by eavesdropping, sudden interruptions and confrontations around every corner. In all that time, however, there's never a moment of sub-text. The plotting sets up moral dilemmas - good versus evil, responsibilities of war, etc - at every turn but they are talked through rather than dramatised, raised and dispatched far too fast. Buffini's best idea is the identity of the mystery man, who Estelle believes to be the Angel Gabriel (shades of Whistle Down the Wind, in which Hayley Mills believes a murderer to be Jesus) but elsewhere we're in Afternoon Theatre territory.

Radio drama, of course, relies on a good story and Gabriel certainly has that, but Buffini is so busy telling it that she never stops to let us in to the real drama.

Julian McGowan's beautifully dressed set creates a perfect sense of period atmosphere, which director Fiona Buffini lets her cast loose upon. An actress of great subtlety, Lisa Harrow, as Jeanne, takes to the melodrama like a duck to water, knocking back the cognac and blazing her way through to survival, while Philip Fox defies expectation by being extremely convincing as a Nazi, from his excellent accent upwards.

Gabriel will make a good TV series, which explains why it has won the LWT Plays on Stage Award. The dramatic tale of the deprivations and dangers of a family under occupation, it's Colditz meets Bergerac, with an episode of The Moral Maze thrown in for good measure.

To 24 May. Booking: 0171-420 0022