Multiple walk-outs and even carry-outs of horrified audience members have been reported from the National Theatre’s revival of Sarah Kane’s Cleansed, and more sensitive readers may want to avoid not only the production but even some of the details in this review.

As Kane took her own life in a psychiatric hospital soon after her twenty-eighth birthday in 1999, her plays now risk what might be called the Sylvia Plath problem – a tendency to look for clues to the outcome in the output, and a sense of robbed promise leading to over-praise of the material that appeared.

Katie Mitchell, a director with a history of treating stage directions as a trampoline for her imagination, darkens the biographical shadow over Cleansed by relocating the action from the derelict university requested in the script to a setting that, in the decor and signage of the design by Alex Eales, clearly invokes the basement of an NHS hospital.