It's clearly a busy time for David Eldridge who has two new plays premiering in London at the moment; despite a shaky start, I would say The Stock Da'Wa is by far the better of the two, and my recommendation if you were to choose between this and the overrated Knot of the Heart. It's a tricky one to review, this one, as it's one of those plays constructed to slowly give the audience clues about what the hell's going on, so almost anything I can say about its themes constitutes a spoiler (in fact as part of the Hampstead Downstairs season it's not being shown to "proper" reviewers; maybe they wanted to spoil Michael Coveney's fun in giving everything away in the opening sentence.) But a quick internet search tells me "Da'Wa" is roughly the Muslim equivalent of "sermon" so the fact that Islamic extremism is among its themes is perhaps not too much of a spoiler. And there is a sermon of sorts being delivered, by Paul (Gary Shelford) who has returned to the village of Stock in Essex, 17 years after leaving the home of Joan (Ann Mitchell,) the mother of one of his school friends and a sort of surrogate mother to Paul as well. He arrives unexpectedly in the middle of the night with blood streaming from a broken nose to confront Joan and her house-guest Mr Wilson (Robin Soans,) a gay former teacher who'd taught him all those years ago.

As usual Eldridge is drawn to pretty depressing themes but here he chooses to do it with large doses of black comedy - in fact the nastier things get, the bigger the laughs seem to be. The tone isn't always quite right - for instance it doesn't feel surreal enough to accept how well Joan and Mr Wilson react to a particularly gory revelation; and while we're alerted to the fact that Paul has consciously made his speech more formal, his sermons are sometimes overly poetical. But it's undoubtedly satisfying on many fronts. Kathy Burke directs, and apart from one gripe (on a reasonably large stage by studio theatre standards, she too often opts to have the characters spread out as far as possible, with someone in one or both downstage corners most of the time; whether it's deliberate or not that this results in actors being slightly out of the audience's eyeline, it's irritating) does an outstanding job, she's coaxed some fantastic performances out of her trio. One of those cases where I kept changing my mind about who was giving the standout performance, Shelford's intensity, Soans' comic delivery or Mitchell's gradual mental and physical collapse are all impressive.

The Stock Da'Wa by David Eldridge is booking until the 14th of May at the Hampstead Theatre's Michael Frayn Space.