The stairway leading to a featureless room stinks of bleach. Inside, a woman vacuums, before abruptly collapsing to the floor. The air is filled with frantic whispers. Outside in the rain a man waits for the woman with a dossier of explicit pornographic images of her that he says were found on the internet. A dog barks. Then the scene, seething with the sinister and unexplained, shifts. We hear the voices of children from a nearby school. A teacher talks of a murdered little girl. Water, and then blood, drips from a ceiling.

Anthony Neilson's new play, written during the rehearsal period and finished just days before its opening, is claustrophobic and clotted with menace. It's performed, in the author's horribly compelling production, behind a black gauze, which turns from opaque to transparent with lighting changes. It's as though we can see through walls, glimpsing the terrors that can occur inside seemingly commonplace homes. It's a nightmarish vision that calls to mind not just the recent Josef Fritzl case, but also Fred West, the Soham murders and the abductions of Madeleine McCann and Shannon Matthews.

Slowly, a central story emerges of a woman who, having once had knowledge of a gruesome crime, is now a fugitive from her past and her guilt. Neilson's writing leaves a trail of teasing clues. One character puzzles over a newspaper crossword, and following the play's layered, disquietingly fractured narrative has a similarly vexed quality. Names turn out to be anagrams; witnesses become victims; the trusted are tormentors; and as characters mutate the actors exchange roles.

Sexuality, expressed in language and in surreal, shocking stage effects, becomes nastily embroiled in the horror, carrying with it a strong whiff of Stockholm Syndrome. Scenes are separated by blackouts that plunge us into darkness. The confusion and fascination emphasise the incomprehensibility of the crimes that the piece evokes, as well as forcing us to question our interest in them. We devour the stories, just as we do when they are served to us, sauced with speculation, in the media.

It's not an experience for the faint-hearted. But it is morally challenging and queasily riveting, and the performances, from a cast in which Nicola Walker, Stuart McQuarrie, Jan Pearson (pictured) and Phil McKee are outstanding, are entirely, absorbingly committed. This is work that disturbingly demands its audience's complicity, and leaves an indelible stain on the memory.

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