In this brilliantly crafted, hilarious comedy, two couples in their own homes, the Fosters and the Phillipses, are visible to us but not to each other. That the characters cross so blithely into each other's spaces is an apt metaphor for the double-dealings brought on by illicit affairs. Telephone calls are made to the wrong wife or husband; idiotic conversations or hang-ups abound. When the hapless Featherstones are invited to dinner, Ayckbourn's strategic ploys step up another unbelievable notch.