We may be accustomed by now to Philip Ridley’s dramatic vision of a somewhat sinister, hermetic East London. But this 1992 work made his name and in one of the most useful revivals of its uneven 50th anniversary season, Hampstead skilfully reminds us of the piece’s unsettling power.

In a peculiar flat above a disused fur factory, 30-year-old Cougar (Alec Newman) prepares to celebrate his 19th birthday once more. He lives in an unhealthy non-relationship with the older Captain Tock (Finbar Lynch). The party is meant to bring to fruition Cougar’s grooming of schoolboy Foxtrot (Neet Mohan) but no one has counted on the intervention of his forceful new girlfriend, Sherbet.

Sherbet’s arrival not only peps up Edward Dick’s production, which until then is focused but under-gripping despite sterling work from Lynch, but also elicits a memorable stage debut from the delightful Jaime Winstone. She displays stiletto-sharp comic timing as she totters about on precipitous heels, pricking craftily at the loathsome Cougar’s Dorian Gray‑esque delusions about youth and ageing. Disquieting and impressive.

Until 17 Oct (020 7722 9301).