Sometimes you want to celebrate the singer more than the song. And the success of Debbie Tucker Green's elliptical 50-minute play about the shock of the unforeseen depends on its vibrant performer, Nadine Marshall. Playing all the characters, she holds the stage, and our attention, with authority.

Green deserves praise for painting a vivid picture of one particular day in the life of a black family. Sister and brother wake on a chilly spring morning with "birds bitching their birdsong outside". The siblings snap at each other before she sets off for work and he slouches off to school. Mum, having burned the porridge, settles down to daytime TV while her taciturn husband wakes from his slumbers. This workaday routine is interrupted when the sister, the narrative focus, gets a peremptory call saying "Come home. Now" and discovers everything has been shattered by an act of random violence.

As in her previous plays, Green reveals a pungent, poetic voice and an eye for detail. But fine writing is not the same as drama. Too much is described not shown: you go to the theatre, after all, to see things happening. The real fascination lies in Marshall's superb ability to bring the four characters, in Sacha Wares's economical production, to life. Marshall effortlessly captures the sister's tense urgency, the brother's laid-back virility, and the slower rhythms of the parents. She also reveals an extraordinary command of mood, first eliciting laughter of recognition from a predominantly young black audience and then producing a pin-drop silence as tragedy erupts. I yearn for a more fleshed-out play but this is a performance to see and savour.

· Until April 12. Box office: 020-7565 5000