The 'soldier' is Niels Bohr, the great Danish atomic physicist whose discoveries made the atomic bomb possible. In 1940 he stayed at his post when Denmark was occupied by the German forces - and stayed there for three more years while the Allies desperately tried to persuade him to escape. Without arousing Nazi suspicions, could they convince Bohr that his knowledge could change the course of the war?
Time had almost run out when, 30 years ago this month, in October 1943, an unarmed Mosquito set out on a hazardous flight to Scandinavia...