People who claim to have seen God whilst on hallucinogenic drugs sometimes tell of a common reaction to the circumstances. Our first impulse on the Day of Judgement, they relate, is neither to apologise profusely nor put up a spirited defence of our behaviour. Rather, it is to try to delay the Almighty, to keep Him talking or distract Him somehow by changing the subject. More sober citizens experience similar thoughts as they flounder in disbelief on discovering they have been taken in by a trickster. The predicament is well documented in this collaboration between the actor David Burke and a sporting dupe Michael Frayn.

Burke played the physicist Niels Bohr in the first cast of Frayn's play Copenhagen, which concerns the visit Werner Heisenberg paid to Bohr in Copenhagen in 1941. At the end of the second world war, Heisenberg, along with the other German scientists who had been involved in atomic research, was secretly interned for six months in Farm Hall, a country house on the outskirts of Godmanchester, in Huntingdonshire. There they ate first-class dinners and entertained each other with piano recitals while the British authorities tried to determine how close they had come to building an atomic bomb. One day during the play's run, Frayn received a letter from Celia Rhys-Evans—a woman purporting to be the subsequent owner of Farm Hall—bringing to his attention a batch of notes and diaries she had discovered beneath the floorboards. Written in German, the scraps seemed to describe events the previous occupants had managed to hide from the guards and their listening devices. Frayn set about the task of translation with a contribution to history in mind, but this entertaining record of folly [Celia's Secret] is the result.

The ingenuity of the trickster is matched only by the ingenuity Frayn shows in suspending his disbelief. He and Burke tell the story of the investigation in alternate chapters, with Burke stealing much of the show. Where Frayn is concerned with damage limitation, his collaborator has clearly thoroughly enjoyed his contribution. Several months into the adventure, a friend puts Frayn out of his misery. The writer then proceeds to display the three faces of the duped. First, there is denial: it seems more likely that his friend is mistaken than that he could have been so gullible. Some weeks later, there is an attempt to share the guilt: he argues, truthfully—but somewhat unconvincingly in this case—that it could have happened to anyone. Finally, he puts on a brave face: ‘I had enjoyed believing; I didn't enjoy not believing.’ A great deal of time elapses in between as Frayn vainly plots revenge in kind.

Unable to turn the tables on his tormentor, Frayn has opted instead for the faithful escape route of the writer who faces ridicule—he turns it into material. As he tacitly acknowledges, however, such medicine is effective only for a single use. Adapted for the stage, the book would make an excellent two-hander, but Frayn wisely rules himself out from playing his own part.