Mercury Fur is savage. It’s vicious; it’s sordid; it’s brutal; it’s vile. People walk out of it. Some cry. Some, reputedly, vomit. It made me shudder, and it made my stomach churn. And when it was finally over it received the biggest ovation I’ve heard in Cambridge yet.

Its premise is not unfamiliar: it stages Philip Ridley’s black vision of a London overrun by refuse and criminality. A strain of butterflies have developed psychoactive properties (we’re never quite sure how), and are consumed near-universally. We follow a dealer in the butterflies and his little sister trying to get by.

An unsympathetic description might characterise it as cobbled-together – a hack’s job, combining well-known dystopias. The ubiquitous hallucinogenic butterflies are not so very different from the ‘soma’ in Huxley’s Brave New World. Degenerate fantasies, re-created in real life for wealthy customers' enjoyment, are A Clockwork Orange’s ‘ultraviolence’. The Hunger Games and its countless antecedents have spoken already of the sick voyeurism underlying mass spectator culture. Post-government anarchy is the stuff of nightmares everywhere.

But that would do little justice to the play. It has a visceral potency, achieved in part through flawless lighting and sound design. Darkly thrilling ambient music accompanies relived memories and revelations. Light moves through every conceivable shade of blue and violet, from mauve to turquoise to lilac and lavender, eerily approximating the experience of consuming the butterflies as we begin to understand it. This is stylized and unnatural, and, in this stylized and unnatural world, extraordinary effective.

One of the effects of sustained butterfly abuse is the degeneration of memory. The past is slipping from Mercury Fur’s characters’ lives, and recalling it becomes an exhilarating act, infrequent and prized. When Naz, in a stand-out performance by Marika McKennel, remembers the murder and rape of her little sister, it is with eagerness and excitement. Only for an instant, at the end, does wonder seem to shade into bewilderment, as if some tiny fragment of her has grasped the full meaning of her account. To be fully conscious under such conditions, to be fully cognizant, is a curse, and Elliot, the butterfly-dealing co-protagonist who never indulges in what he sells, speaks with visible emotion about possessing ‘four more years’. He means the burden of remembering four years more of the ‘pre-historic’ age – of normality – than his drug-addled, simple, dependent sister.

Part of the reason he owns a gun, we realise, is to be able to kill his lover and his sister if “things get bad". This too has its precursor – in McCarthy’s post-apocalyptic masterpiece, The Road. That novel, which contains cannibalism and the indelible image of a baby roasting on a spit, may be Mercury Fur’s closest analogue in tone. Parallels abound: the divide between the new world and the lost old one; a character burdened with knowledge of the latter caring for one who knows only the first. But the differences may be more instructive. The Road takes place in a denuded landscape, stripped of referents, and its slow, quiet hesitations set off episodes of tense danger.

Mercury Fur is in overdrive from the very first. Everybody is on edge, roaring and screaming, violent, at times barely human. When Nas asks Elliot’s sister, Darren, if she has tried combining the butterflies, we recognise the emblematic logic of the play: piling on effects, raising the stakes, ramping up intensity. A performance that is always frenetic, all the time, has nowhere to go. It threatens not to desensitise but to disengage.

And that, finally, is the weakness of Mercury Fur. The cast is excellent. Freddy Sawyer (as Elliot) is always convincing in his intensity; Julia Kass is good as his vulnerable, eager to please sister. But their engagement with the world they've inherited is superficial, an emotional analogue to the superficial excesses that threaten to overwhelm the story. A play as loud as this, which seeks so blatantly to outrage and to shock, should be underpinned by greater thematic depth.