Two great physicists. One conversation. Infinite possible interpretations.

In the fall of 1941, German atomic scientist Werner Heisenberg paid a visit to his mentor, Niels Bohr, "the father of modern nuclear physics," in Nazi-occupied Denmark. The subject of their conversation, and its impact on subsequent scientific, military, and world history, has been debated all the decades since — did Heisenberg warn Bohr about the German nuclear program, or pry for information about the potential of an Allied atomic bomb? Did he earnestly try to prevent the destructive potential of the split nucleus, or was he himself too fragmented to know his own motives, let alone their outcomes? Did Bohr panic needlessly, misunderstanding Heisenberg's intentions, or did he understand them all too well? Copenhagen reunites Bohr, Heisenberg, and Bohr's wife Margarethe, long after all is over and done, to retrace the paths of memory, physics, loyalty, and politics surrounding that inscrutable visit, and try once again to illuminate the limits of what can be understood about the universe, and the darkness inside the human soul.