Donkey Heart (Trafalgar Studios)

When twenty-something Sasha (Lisa Diveney) brings a young Englishman (Alex Large) into the family’s tiny flat for reasons that are not made entirely clear, it’s the cue for repressions to be addressed and skeletons to be prised from the cupboard.

As the premise for a claustrophobic one-set play it’s a fair one and it’s executed with panache by all involved. The dialogue fizzes with convincing cadences and snappy exchanges, and the playwright’s sister, who directs, draws rich ensemble performances from a terrific nine-strong cast.

Nina Raine‘s fluid staging belies the tiny space and indeed turns it to the play’s advantage. Life is so cramped in the cluttered realism of James Turner‘s set that characters practically trip over each others’ feet – and occasionally those of front-row spectators – without missing a beat. Oh for a window… but that’s the point. There is never a moment’s doubt that Sasha and her mother Zhenya (Amanda Root) are terminally bound to this stuffy little space, with idle brother Petya (James Musgrave) encrusted there to make it untidy.

"Now and then a powerful set piece lifts the play to a better place"

The problem, though, is one of substance, or a lack of it. Donkey Heart is a play that wants to have its sharlotka and eat it, for despite an aspiration to social commentary (it alludes to spying and paranoia in post-Soviet Russia) the material seldom rises above the humdrum. As a kitchen-sink melodrama it's closer to EastEnders than Uncle Vanya; and since the buried secret at its heart amounts to so little, the second half is more a famine than a Festen.

False notes abound, not least the implausible idea that, for plot purposes, a ten-year-old boy might think the most exciting app in an iPhone is the voice recorder. And the notion of not one but two near-strangers being offered accommodation in this overcrowded flat take some swallowing, particularly when the striking Natalia (an insinuatingly poised Emily Bruni), seems such a threat to their fragile stability.

Now and then a powerful set piece lifts the play to a better place and suggests that Raine is a writer to watch. Most of these moments revolve around Patrick Godfrey as Alexander, the paterfamilias who has seen it all. The old man may have no difficulty switching off from the incessant family squabbles, but show him a CCCP-emblazoned T-shirt and dark memories pour from his scarred depths.

Godfrey, still the mesmerising presence he’s been seemingly forever, projects haunted emotions and unbearable loss. The octogenarian's tender exchanges with his young grandson (the assured Albie Marber, who alternates in the role with Pierre Atri) have, we come to learn, a foundation of special significance. Elsewhere he revels in dry one-liners, as when Alexander advises his wayward son Ivan (Paul Wyett) to solve his marital problems by frequenting prostitutes. "You don’t look at the chimney when you’re poking the grate."