In 1941, in the middle of the Second World War, the great German physicist Werner Heisenberg made a strange trip to Copenhagen to see his Danish colleague Niels Bohr. They were old friends and collaborators, and together in the 1920s they had begun to lay bare the mysteries at the heart of the atom. But now Denmark was under German occupation, the meeting was fraught with danger and embarrassment – and Heisenberg was burdened with a terrible secret.
Why he went to Copenhagen and what he wanted to say to Bohr are questions which have exercised historians ever since. In Michael Frayn’s multi award-winning drama Heisenberg meets Bohr and his wife Margrethe once again to look for the answers, and to work out, just as they had once worked out the internal functioning of the atom, how we can ever know why we do what we do.