A Fringe First winner at this year's Edinburgh Festival where it was premiered at the Traverse, Morna Regan's debut play Midden now arrives at Hampstead Theatre as a solidly constructed, superbly acted but surprisingly unsurprising play about female family life.

Midden is set in the Derry, Northern Ireland home of Ruth Hegarty's Ma, who shares it with one of her daughters, Aileen (Emma Colohan) and her Altzheimer's-suffering mother Dophie (Barbara Adair). The story revolves around the homecoming of Ma's other daughter, Ruth (the fine, sensitive Michelle Fairley).

Ruth has returned from America, where she's built a successful fashion business with childhood friend Mab (Maggie Hayes), also back home for a visit. But all is not well in her adopted country - Ruth has walked out of a relationship even as she and her partner were in a shop ordering yellow orchids for their impending wedding. Instead of shelling out to the florist, we learn, Ruth popped into the travel agents next door and bought a one-way ticket home.

That change-of-plans revelation, and many like it, are only slowly revealed. Regan's play is crafty at withholding and then revealing factual information, for it has a larger purpose: to crack open the secrets, and especially the resentments, that lie buried within family life. This it does by stealth rather than sledgehammer.

For such sensitive qualities, Midden has rightly been much admired. Likewise for its differentiated, disappointed characters - parts which the play's actress-turned-author creator has seen to making eminently actable. But the piece is ultimately unsatisfying because its trajectory is always so deeply predictable.

Still, Lynne Parker's production for Rough Magic Theatre Company, one of Ireland's leading new writing companies, does offer the promise of discovering a playwright of real craft. Now all we need is more art.

- Mark Shenton