Mariana Pineda, Arcola Theatre, London <!-- none onestar threestar fourstar fivestar -->

Lorca's first theatrical success, is something of a rarity, but it is an appropriate choice to open the Arcola's season marking the 70th anniversary of the poet's death. Pineda was a popular Andalusian heroine - the play opens with children singing a ballad about her - who was garrotted by a repressive regime in 1831 for sewing a banned flag and helping a revolutionary leader to escape. The play seems to illuminate Lorca's own death at the hands of the Falangists during the Spanish Civil War, although he wrote it a decade before.

The play is in two scenes: in the first, which lasts almost an hour, Mariana is seen at home, a widow with two young children, beloved of everyone who knows her, you gather, for her beauty and virtue.

She is visited by three men: the decent, self-sacrificing Fernando, who is in love with her; Don Pedro, her lover, an escaped revolutionary, in whose honour she is sewing the flag; and then the police chief Pedrosa, who is pursuing Pedro, but who also has designs on her.

The somewhat melodramatic plot is punctuated by episodes and bursts of overwrought dialogue that seem more characteristic of Lorca. The other women of the house gossip about her embroidering - "The crimson thread between her fingers seemed a bleeding wound carved in the air" - and a friend tells of a day of dancing and bullfighting - "Each wound a red carnation."

It is in the second half, as Mariana awaits execution in a cell in a convent, that the play takes on real imaginative life, and breaks out into poetry. Though to the outside world it appears that Mariana's political convictions enable her to maintain dignity in the face of death, it becomes clear that she is not preparing for martyrdom: she is simply convinced that her lover is plotting to rescue her. When she realises that this is not the case - that he loves freedom more than he loves her - she is dismayed; her death is not a triumph, but an act of submission. Political freedom is mixed up with, and perhaps eclipses, erotic freedom - and this freedom, Lorca suggests, is illusory, because our hearts are so often our enemies.

Max Key's staging treats this uneven but intriguing piece respectfully, and comes up with some properly theatrical gestures, such as the opening of the second half, in which veiled nuns enter in candlelit procession.

Jon Bausor's set - naturalism dissolving into tattered abstraction at the edges - is effective. Gwynne Edwards's translation is tactful, acknowledging the play's verse-form but allowing it to obtrude only in the occasional obvious rhyming couplet.

As a whole, though, the production is frustratingly restrained, never rising to the heights of passion that might make sense of the text: the encounters between Mariana (Pandora Colin) and her upright would-be lover Fernando (Geoff Breton), in particular, feel less like Blood Wedding than Brief Encounter.

To 19 August (020-7503 1646)