Copenhagen

September, 1941. Nazi Germany has invaded Poland, Norway, France, Greece, and the Low Countries. Werner Heisenberg, a leading German scientist, makes a quiet trip to occupied Denmark to visit Niels Bohr, his mentor in nuclear physics. Both men have investigated fission; within the crucible of war-torn Europe, they talk physics. But nearly as soon as he has arrived, Heisenberg abruptly returns to Germany. What transpired in Copenhagen? What do we know? What can we never know?