Infamous for harrowing violence and intense psychological impact, Sarah Kane's plays have cult status in the radical school of 1990s in-yer-face theatre. They are not entertainment; it's the kind of theatre that makes headlines, splits opinions and inspires charges of 'filth' and 'brutality'.

And, seventeen years after her suicide (aged just 28), Kane still provokes a controversy. A writer of gratuitous, sadistic violence, or one of history's most important and innovative female playwrights?

One thing's for sure, in the safer, male-dominated days of Nicholas Hytner's reign, the National Theatre was acts away from such divisive, disturbing plays as Kane's Blasted, Crave or Cleansed. But now, under Rufus Norris' 'broader church' vision of a nation's theatre that has 'something for everyone', Sarah Kane will finally be staged at the National -- fittingly, at the hip, recently revamped Dorfman Theatre.

Cleansed marks director Katie Mitchell’s anticipated return to the National Theatre, and it is an unyielding, calculated, and stifling homecoming. Reports of audience members fainting and walking out circulated throughout previews. With visually violent acts including rape, brutal torture by metal rod, mutilation, and eye injections, Kane’s Cleansed is an exhausting and unsettling piece of theatre.

Desperate to reunite with her brother Graham (Graham Butler), Grace (Michelle Terry) finds herself trapped in what originally was a university in Kane’s script, but which Mitchell transforms into a semi-abandoned drug treatment facility. In charge is the tyrannous Tinker (Tom Mothersdale), and with a push of any three switches onstage switches, a klaxon blares and figures in black balaclavas literally roll on episode after episode of extreme and relentless brutality. The quick, mechanical processes by which torture devices are plugged in, doors are opened, and wheels are unlocked is contrasted by often beautiful slow-motion sequences which heighten Kane’s imagery and create a cruel and contorted world.

Ambient noise and suffocating sounds are employed meticulously to reflect the traumatic events that Grace (and the audience) can barely watch. Mitchell’s direction focuses on anguish derived from watching pain as much as experiencing pain: Rod (George Taylor) must look on, a gun pointed at his head, while his lover Carl (Peter Hobday) has his limbs lacerated. Graham tries to encourage Grace, telling her it doesn’t hurt as much if you know it’s coming, and yet the events that follow seem to undermine his affirmation. Terry, Mothersdale, and the rest of the cast are gripping in a play which must be as draining to perform as it is notoriously difficult to stage and watch.

Amidst the suffering, Cleansed is ultimately an exploration of love. Ted says to Carl: ‘I love you now. I'm with you now. Now. That's it. No more. Don't make me lie to you’. Steadily yet mercilessly, love is stripped of its artifice and of its dignity, laid bare upon the stage. And somehow, against all brutality, it remains intact. Kane’s Cleansed is certainly not for the faint-hearted, squeamish or conservative, but it is a probing and powerful piece which proves its own lasting power.

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