The work of the late Sarah Kane has been belatedly recognised as that of genius, even by some of those who were her fiercest critics when her first play was staged by the Royal Court in 1995.

There are multiple rapes, suicide, cannibalism in that work, so perhaps the general hysteria of 1995 was understandable. Yet seeing Blasted anew last night in a new production at the Soho Theatre, it is clear that this is in no way shock for the sake of shock. Without the distancing effect of the actor-delivered stage directions and the matter-of-fact delivery this could just be Hollywood-style sexploitation, without the defracting, deceiving mist of the camera lens. But never for a second does it feel like that.

Certainly the relationship between the young, highly vulnerable Cate (Jennifer-Jay Ellison) and the middle-aged, cynical, violent Ian is shocking, but its very complexity is its best defence. Kane explains Ian, presents him as human, while never excusing his actions. And in the second half, as the city of Leeds falls to some unnamed invading force, we are in a more surreal world, yet a world that has a feel of truth.

And despite this careful distancing effect, all of these obvious Brechtian devices, these are characters, even the nameless Soldier, with whom one immediately feels sympathy and identification. They are never simple, never predictable. This is, simply, a great play, its language masterful in its rawness. Who could top: "I loved Stella until she became a witch and fucked off with a dyke"?

Yet the new production goes further, finds something new, and newly shocking, in the script. It is by the Graeae Theatre Company, which brings together disabled and non-disabled actors, writers, and audiences. So it is that two of the main three actors in this production of Blasted are visibly, significantly, disabled. And that presents the polite, carefully cultivated sensibilities of the average audience member, and reviewer, with a dilemma. We've got used to colour-blind casting - barely turn a hair at a black Roman emperor or Tudor monarch.

But here, in the brutal, dangerous world of Kane's shadow Leeds, what are we supposed to do? Director Jenny Sealey eventually makes it clear, in one disturbing scene of male rape: we are supposed to acknowledge the fact of the disability, to accept it, to deal with it.