Sarah Kane’s Cleansed is a tangled tapestry of torment. It depicts torture, rape, hanging, mutilation and murder. It has a couple of softer moments, in which lovers make sacrifices for one another, declare their love or lock together in tender embraces, and these almost seem to stand for the redemptive power of love. That each such moment is followed with grotesque brutality – Rod is stabbed in the throat because he asks the authorities to spare Carl, Tinker shoots his partner in the head moments after telling her that he loves her – gives some indication that affection and violence sit close together in Kane’s dramatic world. Kane is best known for 4.48 Psychosis and Blasted; both are disturbing portraits of physical and emotional violence. Her oeuvre includes just five plays, written before her suicide at the age of 25 in 1999. It would be crude to read Kane’s works as autobiography (‘her depression explains her characters’), but an undeniable sense of futility subtends them all. It is not hard to connect the anguished playwright with these agonised protagonists.

Kane’s text sets Cleansed in a university-turned-torture-institution. Katie Mitchell’s production re-houses it in the shell of a bombed-out hospital. Guards with stockinged faces wheel strait-jacketed inmates perilously across stage. Their uniforms are only made more ominous by contrasting bare feet, which suggest childlike domesticity even as they work as priests in a temple to torture. At Guantanamo Bay and Abu Ghraib, prisoners’ faces were covered before their abuse. Michelle Terry’s Grace – locked in a coin-operated cubicle and forced to dance seductively – also wears a hood. In this regard, Cleansed shows us the links between grand atrocities and the more gentle horrors of sexual objectification.

Trivial they may seem, but in a play packed with visceral violence, the stunt props had better be perfect. Fortunately, we see Carl’s hands and feet shorn away to bloody stumps by a shredding machine without a hitch. When Rod is stabbed in the throat by Tinker, he dies a slick and believable death. Even the infamous anal rape scene is, hideously, believable. These details matter, particularly in Kane’s work that has so often been pigeonholed as an assault on realism. Whilst Cleansed breaks utterly with dramatic naturalism, it nonetheless holds up a mirror to the very real atrocities of the last century. It exposes us as audiences who leer over documentary disaster porn, while eviscerating our excuse that we are just watching real-world events.

When critics accused Blasted of being gratuitously violent and devoid of meaning, Kane hit back. Blasted was about the continuities between the evil one might perpetrate in a Leeds hotel room and the atrocities of the twentieth-century. “The logical conclusion”, she observed, “of the attitude that produces an isolated rape in England is the rape camps in Bosnia and the logical conclusion to the way society expects men to behave is war” (Ken Urban, An Ethics of Catastrophe: The Theatre of Sarah Kane). With this in mind, it is easier to understand Kane’s claim that Cleansed was inspired by a Roland Barthes line that “being in love is like being in Auschwitz”. The vile and violent aspects of love so often come together in her characters’ tortured cries about faith and betrayal.

The acting is superb: distressingly, hauntingly, achingly excellent. Terry’s Grace is demonic in her distress, Matthew Tennyson’s Robin is as raw and tender as a wound, and Tom Mothersdale’s Tinker is the kind of baddie to trip straight into your nightmares.

With flawless acting, credible staging and horribly apt execution, Mitchell’s production does Cleansed justice. It is a rough and raw justice, the kind meted out by sadomasochistic gaolors and pseudo-doctors, but it is honest too. Mitchell’s interpretation means Cleansed does exactly what Kane’s script demands: it gives equal regard to the intimacy of violence and the violence of intimacy.

Cleansed is playing at the National Theatre until 5 May. For more information and tickets, see the National Theatre website. Photo: Steven Cummiskey