Martin Crimp was launched as a playwright by the Orange Tree in the 1980s with a series of deft and funny plays, since when his style has toughened into the sinister, disturbing and often ambiguous domestic dramas of recent years.

In this Orange Tree double-bill, marking Crimp’s debut as a director, he pairs one of those early successes – Definitely the Bahamas – with a new piece, Play House; both plays define that transition and reawaken an earlier, freer and more light-hearted mood and mode of writing.

The new play is virtually a jeu d’esprit for a sexy young couple, Simon and Katrina, setting up home, annoying the neighbours, cleaning the fridge, having sex upside down and skirting the madness and spiritual skeletons that stalk Crimp’s later characters.

He is a departmental head of commercial planning, she is a teacher, and they are beautifully played, at a frantic pace, by Obi Abili and delightful newcomer Lily James, composing a kaleidoscope effect of snapshot scenes that are both exhilarating and strangely enigmatic.

Crimp wittily exploits the radio play origins of Definitely the Bahamas by placing the married couple, Milly and Frank, at facing green baize tables in a recording studio, chatting spikily about their strained marriage and the compensatory brilliance of an unseen child, Michael, who has some murky connection with the silent Dutch student, the elephant in the room disguised as Lily James.

The presentation emphasises how so much of Crimp is all in the words without ever quite packing the theatrical punch of Harold Pinter at his best. Perhaps this is how Katie Mitchell, Crimp’s frequent collaborator these days, might have directed the play, but it comes across as a diluted, comic version of a Wooster Group production.

Still, it’s an intriguing, absorbing game of cat and mouse that is played out by the ever smooth and subtle Ian Gelder and the increasingly neurotic and flaky Kate Fahy. And it all makes for a touching, civilised birthday present for artistic director Sam Walters in his 40th anniversary year in the marvellous little theatre he founded.