This Wide Night, Soho Theatre, London

Prison doesn't end once the prisoner is expelled through its gates back into the world. Psychological incarceration may persist; the freed person may remain institutionalised. A stint in prison can, of course, be the making of some people. Banged up for defacing library books, Joe Orton developed the detachment and complete disrespect for power and authority that turned him into a formidable comic playwright. On his partner, Kenneth Halliwell, sent for the same offence to another institution, prison had the opposite effect, resulting in an agoraphobia of the soul that made him increasingly claustrophobic to be with and finally leading to his death.

Lorraine and Marie, the released duo in Chloe Moss's sensitive and funny-sad two hander, This Wide Night, are the opposite of Orton and Halliwell in every way. Fifty-something Lorraine and thirty-something Marie did not know one another before becoming cell-mates and now, back in civvy street, they have to grapple with the contradictions of a position that is (from one perspective) very intimate and (from another) irksome, because it's based on something that should be over and done with, but isn't. The scene is Marie's poky bedsit from which she is finding it increasingly difficult to emerge. Concerned about her friend and hoping to take up an offer of co-habitation that Marie is now regretting, Lorraine arrives and the drama of mutual support and reciprocal restriction is played out.

Maureen Beattie and Zawe Ashton, as the older and younger woman respectively, deliver emotionally subtle, gently humorous performances in Lucy Morrison's well-judged production for Clean Break, the company that specialises in plays about women and the vagaries of the legal system.

The writing has a wounded, stoic quality that benefits from, but wears lightly, the fruits of first-hand research. The specificities catch the light. I liked the detail of the cellmate who had attempted to do herself in with "a knee-length sock" – and Moss valuably notices how susceptible to indignities is the life of the ex-prisoner, whether from social workers banging on in their purportedly galvanising jargon about "strength" or from employers who are scarcely out of short trousers and don't understand the difficulties.

To 5 December (020 7478 0100; www.sohotheatre.com)