Cavity was glitteringly original. Sean Grundy's play was a comedy about adultery, fast, sexy and I'd have said 'edgy' too, if that word hadn't recently been bled of meaning. Here, I intend it to convey going as close as possible to the borders of descriptive propriety while employing sharp wit to induce a slightly shocked delight. Alison Crawford directed a marvellous cast - Julian Rhind-Tutt, Ingrid Oliver and Kerry Godliman - with glorious assurance. Afternoon Play is not often as utterly entertaining as this. Everyone, me included, usually moans about it. Frequently, these days, we must admit we can be wrong. If you missed Cavity, you missed a treat.

Is there a word for people who enjoy intercourse through holes, or for those who prefer living in dark confined spaces? Playwright Sean Grundy's macabre comedy is about a woman who discovers a taste for both. Kirsty, our ill-fated heroine, recounts in solemn tones how a lunch-hour fling with work colleague Adrian goes disastrously wrong when his wife returns home unexpectedly. Kirsty hides in the attic, but rather than escaping later, she and Adrian realise there are bizarre, sensual pleasures to be had from romancing through cavity walling. Adrian drills holes around the house through which to communicate with Kirsty and she recommissions a chemical loo she finds in the loft. Then he gets his wife to buy long, thin food. It begins as a farce and merrily climbs the heights of absurdity but it's very amusing along the way.

Sharp, sexy, surreal yet somehow utterly believable comedy by Sean Grundy. Adrian (Julian Rhind-Tutt) starts an office romance with Kirsty (Ingrid Oliver). He takes her home, thinking his wife, Lucy (Kerry Godliman), is away. But she comes back unexpectedly. Kirsty hides, falls into the cavity wall. One thing leads to another, and she stays. And stays. This brilliantly observed piece is not for those who shy at on-air sex. But for anyone who relishes characters who come to life in a situation which grows around them almost magically, don't miss it.

A very odd comedy by Sean Grundy of the sort you suspect could only work on radio. Kirsty hides in the attic when the wife of the man with whom she's having an affair returns home unexpectedly - but in her panic, falls into the house's cavity wall. Rather than escaping, she and her lover Adrian discover that there are pleasures to be had from the predicament...