A second world premiere of a Tennessee Williams play at the Cock? Surely this cannot be. But A Cavalier for Milady, recently found in the writer’s papers, and written very near the end of his life, proves a fascinating coup, a concentration of many great Williams themes but with an unbuttoned sensuality of language.

It’s as if Williams didn’t expect or want this 75-minute Cinderella charade to see the light, it’s so free and raunchy. In yet another portrait of his poor, lobotomised sister, Rose, he expresses sexual yearning with unprecedented candour; and brings Nijinsky back from the dead!

Woman child Nance, dressed as a virginal communicant, is left alone with her masturbatory fantasies, while her ferocious mother hits the town, and the bars, courtesy of an escort agency, with a similarly louche and hedonistic friend. Nance dreams at the statue and, lo, it comes to life, clad in the mottled fawn tights of the great dancer.

While the young couple - Cinders and her muscular, bare-chested Buttons - play a teasingly explicit “don’t touch me” fandango, the ladies who lunch at beauty salons go to the ball on their poppers, wrestling with younger men in the back of taxi cabs and around the forsythia bushes.

Janet Prince and Lucinda Curtis play the broads like drag queens, perhaps overloading the not-so-coded gay message. How fabulous if they’d been, well, fabulous. But Gene David Kirk’s otherwise hilarious and sensitive production proves yet again that there is no such thing as a minor, forgotten Williams play - early or late - not worth seeing.

Gillian Hanna plays the disgusted Irish baby-sitter, while Sam Marks beautifully evokes Nijinsky’s repertoire on a sixpence, and looks wonderful. Caitlin Thorburn makes Nance as forcibly touching as Laura in The Glass Menagerie, and not at all wet. Damp, maybe, but not a damp squib: oddly experimental and fearlessly frank.