It’s always hard to follow a first big success with a second play, but Polly Stenham has pulled off a magnificent follow-up to That Face, mining a similar seam of personal material in her portrayal of three young siblings left to fend for themselves in a dysfunctional family.

Mum’s in charge, but only in the most haphazard of fashions, in both plays. But whereas Lindsay Duncan’s alcoholic incestuous wreck dominated That Face, this time round mother’s gone missing – she’s on anti-psychotic drugs and verging on the suicidal - just one week after the family (Dad died of cancer) has moved into a new apartment. The stage is strewn with packing cases and there’s no food in the cupboards apart from unwanted jars of organic jam. So young teenagers Eliot and Maggie – so named, possibly, in honour of the poet and Mrs Thatcher – have taken charge of their seven-year-old brother Finn and created their own brand of tribal domesticity in defiance of the outside world, sleeping by day and cavorting by night.

They have found £200 in one of the packing cases and Eliot makes sorties to bring home Chinese meals for breakfast, or bottles of cider in between chatting up a new girlfriend, Cassie. An upstairs neighbour shouts down about the noise. Maggie starts the play screaming about a rat and ends it, bloody and morose, torn between escape and despair.

As before, Stenham reveals a natural talent both for articulating teenage angst and obduracy and for structuring her narrative so that an essentially inert situation retains theatrical momentum. Jeremy Herrin again proves an ideal director, and his casting is spot on. Young newcomers Toby Regbo and Bel Powley are absolutely brilliant, both irritating and heartbreaking, as Eliot and Maggie; neither they nor Stenham once sound a false note in charting their affection and rivalry.

And little Finn Bennett as Finn (sharing the role with Austin Moulton) plays up the deliberate parallels with Maurice Sendak’s Max in Where the Wild Things Are as a focal point in the fantasy games. Georgia Groome is Cassie, Eliot’s appalled girlfriend, and Caroline Harker and Tom Beard call by as Mum’s friends to create a savage plot twist.

Robert Innes Hopkins designs a spacious, well-appointed but neutral white flat that is magically transformed into a birthday party play area after the interval, and the Court’s high standards of lighting and sound are maintained by Neil Austin and Emma Laxton.

- Michael Coveney