Emlyn William's semi-autobiographical play about an illiterate Welsh miner who gets to Oxford thanks to an inspirational teacher is an exceptionalist slice of feelgood naturalism.

But director Dominic Cooke refreshes this Pygmalion meets Dead Poets Society tale with an entertaining metatheatrical spin, and Nicola Walker brings her customary emotional heft to the bracingly unconventional Miss Moffat, who arrives in an impoverished mining town bent on educating its children.

Williams wrote his 1938 drama in Monte Carlo and Cooke undercuts its sentimentality by having Gareth David-Lloyd's black tie toting playwright step out of a glittering party to conjure his characters from stage directions in bare space - authoring his own escape from the Welsh valleys to the sound of Christopher Shutt's radio play-like sound effects.

The trope of a chorus of black-faced miners accompanying Williams' creative efforts can perhaps be excused by their beautifully evocative Welsh language harmonies, and the idea that he's looking back with dewy eyes. By act II, designer ULTZ's set is fully realised - a book-lined improvised schoolroom where promising pupil Morgan Evans learns the language to articulate his desires from the autocratic Moffat.

There's plenty of laughs - although characters from Rufus Davies' Bufton Tufton squire, to Evans himself are slimly drawn. The boy is a blank slate onto which people project their hopes, but Iwan Davies makes his two big speeches count, and fabulously unmaternal housekeeper Mrs Watty (Jo McInnes) and her clear-eyed daughter Bessie (Saffron Coomer) feel quite feminist and contemporary.

Walker brings nuance, passion and excellent comic timing to the dry-witted, Miss Moffat - suggesting the frustrated bossiness of a liberated woman who can only get to Oxford vicariously.

Underlying Williams' nostalgia are harder truths about the slender choices for women and the working class. Education was the only way out for many, and David-Lloyd's anguish reflects the disconnection from community and self of the upwardly mobile. Williams himself had a breakdown at Oxford and the final embrace between his older and younger self may be schmaltzy but feels earned.