Neil LaBute, who offers audiences a feel-bad after-glow to take home with them, has issued another cautionary warning about family life. In a Dark Dark House, whose comma-less title would nicely suit a Fifties B movie, we are asked to savour and then be shocked by the cruel things American males in middle-class families do to each other and have done to them. I was surprisingly held in LaBute’s almost vice-like grip, kept in mystified suspense about just what people are up to in Michael Attenborough’s taut production.

Yet the ease with which intimate secrets are spilled out in the finale struck me as false and contrived, as if to inspire a collective audience gasp of surprise. On this occasion LaBute’s menu of horrors includes a speciality dish new to him: two brothers, Terry and Drew, hark back to when both appear to have suffered gay sexual abuse by an older teenager. What is more, Terry was beaten so hard and so often by his father, perhaps for sexual and sadistic reasons, that he retaliated by trying to kill him. In a Dark Dark House considers how the malady of abuse has lingered on and helped mis-shape their lives, leaving the brothers in unfraternal disassociation.

That, at least, is how it appears. But in LaBute you know that nothing is quite what it seems until the final truth-telling. Staged in 85 minutes and three scenes on Lez Brotherston’s manicured, double-level grassy grounds of a hospital, which later becomes a putting-green and a rich man’s garden, a 35-year-old, permanent adolescent businessman Drew, brilliantly played with phoney charm and subsequent anguish by Steven Mackintosh, is ensconced in the addiction unit to rescue him from the dependency which threatens his marriage. He wants help from his older brother, David Morrissey’s loudly belligerent Terry, a Kuwait veteran and  security guard. You can see the social- emotional distance between them at a glance, though Morrissey lays awkward over-stress on Terry’s alienation.

The play’s big issue relates to loyalty, self-deception and mendacity. Will  Terry corroborate Drew’s story that his addictions relate to long-ago gay abuse, thereby enabling him to escape prison on a dangerous driving charge. His agonised confession sparks a disturbed response from the unmarried Terry  who reveals he so suffered at the same youth’s hands that he remains unsure whether he is now gay himself. That note of uncertainty is sustained in the second scene where Terry picks up a teenage girl, played with casual, seductive naturalness by Kira Sternbach, and finally in the brothers’ reunion after Drew is supposedly cured.

It would be unfair to reveal the significance of Terry’s encounter with the girl or what lies, secrets and not quite believable betrayals lie behind the brothers’ tribulations.

But LaBute draws his devious, devastating plot-lines together to imply misleadingly that a teenager who falls in love with his gay seducer will then lead a life of sexual abstinence and despair.