'A kind of loving' might be a good sub-title for this impressive first play, last year’s winner of the Verity Bargate award, by In-Sook Chappell, a 34-year-old Anglo-Korean who was born in Seoul and raised in Chelmsford, Essex. Like her heroine, Miso Blake, Chappell was adopted in Britain; unlike Miso, she has never had any contact with her biological family.

Miso, an Essex girl who grew up in Southend, returns to Seoul, finds her brother, a taxi-driver called Han Som Kim, whom she has not seen for 25 years, and develops an impassioned sexual relationship with him. They become embroiled in the underworld of businessmen and bunny girls.

It’s all deeply felt, this sense of a twin or a sibling being another part of yourself – something Shakespeare writes about incessantly – and the incestuous reunion carries with it a powerful fulfilment; Han at one point asks Miso to curl around his own body like a shell, while Miso feels him inside her before he’s even got there, so to speak.

Jennifer Lim is a wonderful Miso, sexy and driven but also burnt with two brands of guilt. First, she left her younger brother in the orphanage after their parents both met watery graves. Second, she knows what she’s doing is wrong, but doesn’t understand why she should feel that.

Lisa Goldman’s production picks its way delicately through this emotional minefield. As in all good plays, there is an awful lot we can imagine without having it spelled out for us. Mo Zainal is excellently locked up as Han, finally redeemed by his sister’s generosity of spirit and her tragedy.

Jon Bausor’s design creates a series of shiny interiors that also take us to the heart of the Korean sex industry, where Matthew Marsh’s seedy married hotel proprietor ambushes Miso the minute she appears to raise money; a complete world of sex traffic and human cargo is evoked in these scenes, topped with Marsh doing some 'dad' dancing after a quick servicing under the table cloth.

Other roles of critical interpreter, svelte and bitchy fashion agent, sexy waitress and caring nurse, are beautifully played by Sonnie Brown and Elizabeth Tan. There’s almost too much going on in this play for its short ninety minutes duration; but it’s a real find.

- Michael Coveney