SOURCE: Powers, Thomas. “The Unanswered Question.” New York Review of Books 47, no. 9 (25 May 2000): 4, 6-7.

In the following review, Powers describes Copenhagen as “wonderful theater,” noting that Frayn addresses moral issues of depth and complexity.

Something happened—some terrible offense was given which could never be recalled—during the wartime visit of the German physicist Werner Heisenberg to the man who probably meant most to him in the world, the Danish physicist Niels Bohr. It would be forgotten now, certainly Michael Frayn never would have written a play about it, if the offense had not somehow involved Heisenberg's role as a leader of the German effort to invent atomic bombs. But the bomb was part of it and scientists and historians have been arguing about what happened ever since.

Here is what is known: in September 1941 Heisenberg traveled to Copenhagen, where he told Bohr that in Germany a research...