In a brilliant coda to the play Copenhagen, Michael Frayn receives mysterious letters that take him back to the theme of his bestselling novel, Headlong -- human folly, this time his own. Michael Frayn's Copenhagen has established itself as one of the finest pieces of drama to grace the stage in recent years. The subject of the Tony-winning play is the strange visit the German nuclear physicist Werner Heisenberg made to his former mentor, scientist Niels Bohr, in Nazi-occupied Copenhagen and the quarrel that ensued. Heisenberg's intentions on that visit, for good or for evil, have long intrigued and baffled historians and scientists. One day, during the British run of Copenhagen, Frayn received a curious package from a suburban housewife, which contained a few faded pages of barely legible German writings. These pages, which she claimed to have found concealed beneath her floorboards, seemed to cast a remarkable new light on the mystery at the heart of play. As more material emerged -- specifically notes that appeared to give instructions on how to put up a table-tennis table but perhaps containing important encoded information -- actor David Burke, who was playing Niels Bohr, began to display extreme, even suspicious interest in Frayn's growing obsession with cracking the riddle of the papers. And Frayn, for his part, lost all sense of certainty. Was he the victim of an elaborate hoax? By turns comic and profound, The Copenhagen Papers explores the conundrum that is always at the heart of Frayn's work -- human gullibility and the eternal difficulty of knowing why we do what we do.