When it comes to heartache, unrequited love tends to steal the headlines. But, as Terence Rattigan suggests in The Deep Blue Sea, mismatched love can equal it in agony. In this painful 1952 play, Hester Collyer has abandoned everything – marriage, home, financial security – to live in two shabby rooms with Freddie, her younger lover. But while she has his affection, she doesn’t have his heart. The more she dotes on him, the further off he moves.

As a gay man, Rattigan knew about forbidden love; he also knew about obsessive, one-sided affairs. His play, though neatly structured, throbs with pain. And what he pinpoints brilliantly, and Greta Scacchi brings out beautifully here, is the fact that Hester knows her behaviour is folly and is torn between engulfing despair and a very English common sense.