Not since Sarah Kane’s Blasted can I remember a play as harrowing to watch as Pests. The Royal Court have never shied away from exposing uncomfortable truths. Nor indeed have Clean Break, the 35 year old company set up by female ex-prisoners to give voice to their experiences and enable fresh starts.

Put them together with award-winning playwright Vivienne Franzmann (Mogadishu, The Witness), Manchester’s Royal Exchange from whom she was awarded her first playwriting prize, the Bruntwood and two remarkable actors, Ellie Kendrick (The Low Road at the Royal Court and the title role in the recent The Diary of Anne Frank on tv) and Sinéad Matthews (NT’s Blurred Lines and Black Mirror – Be Right Back for Channel 4) – and you have something explosive.

Franzmann has been involved with Clean Break for three years, as writer in residence and teacher. Before that, she taught in London secondary schools. Can it be a coincidence that Pests is all about education – or lack of it; about language – or lack of it? Or that Franzmann’s two protagonists, Pink and Rolly, like so many women inside, have literacy and mental health problems?

Rolly and Pink are sisters. Rolly, heavily pregnant has just come out of prison. What ensues in Joanna Scotcher’s immersive, mattress strewn set and Lucy Morrison’s shattering, disturbing production is an encounter with lives destroyed by the past, by drug addiction and crucially, by a loving but desperately damaging co-dependency.

It takes some stomach to watch the strung out Pink, besieged by hallucinatory demons in the shape of digitalised lava flows and speaking in an extraordinary invented language as she entangles the illiterate Rolly in order to keep her locked into her world.

As events in their early childhood become apparent so a vicious cycle of addiction, violence and prostitution is revealed as is the scoring – in the score Pink needs to settle with Rolly from childhood and in their colluding heroin addiction.

At the heart of Pests is compassion but I can’t remember anything so brutally poetic since Kane nor so frank in its depiction of drug addiction.

Theatre at its most raw but brilliant and, I wouldn’t be surprised, award-winning.