THE FRINGE / Water, water, everywhere . . .: Sarah Hemming on September Tide at the King's Head and Dona Rosita the Spinster at Pentameters, NW3

The tide is not the only thing that swells unpredictably in Daphne du Maurier's play, September Tide (revived at the King's Head, N1). From the moment Stella Martyn introduces herself to her new son-in-law, Evan, with a husky 'Do I kiss you?' it's clear that both characters are about to be plunged into deep waters of a metaphorical kind. Sure enough, the beautiful but selfless Stella finds herself struggling with a wave of un- maternal feelings for Evan. But this is the Cornish coast, 1948; and they know how to deal with tempestuous conditions.

One trouble with Du Maurier's play is the creaky structure: the illicit attraction is established for the audience within 10 minutes, yet we have to wait a further hour before it is out in the open. Since little else happens in that hour the overwhelming effect is one of predictability. The other problem is the dialogue which sometimes dives to alarming Mills and Boon depths. If you can take the sillier aspects of the play, however, it has an old-fashioned charm mixed with a fascinating risque element: Du Maurier is tangling with incest and free love in the Forties, after all. It's soon clear that Evan (Brendan Coyle) and his young wife Cherry have 'opened their presents before Christmas', as they say in Cornwall, and that, once married, they seem to have ceased sharing a bed. In the face of this bohemianism, Stella's frequent protests that 'your generation don't understand' are not surprising and the linchpin of the drama is the clash of these two worlds. Will Evan loosen Stella's moral stays?

Mark Rayment's sensitive production wields a fine cast. Mary Chester and Francesca Hunt lend depth to the apple-cheeked housekeeper and the strange, hearty Cherry, and Susannah York is perfect as Stella: fragile, utterly charming and self-denying to a fault.

A patient and selfless woman is the centre of Lorca's Dona Rosita the Spinster (Pentameters, NW3) too. In this tale of Rosita, who wastes her youth waiting for a faithless fiance, we find Lorca again dealing with the plight of trapped women, but in lingering, mysterious and lyrical mood: Rosita is constantly likened to a rose in her uncle's garden that withers in the same day as it blossoms. Andrew Pratt's atmospheric production deals skilfully with the play's combination of poetry and comedy, and contains a lovely central performance from Daphne Nayar.

King's Head: 071-226 1916; Pentameters: 071-435 3648