Quint Munroe loses his oldest friend, Squadron Leader David Scott on a mission to destroy a group of German V-1 launchers, and Quint must break the news to his wife Beth, with whom Quint had once been involved. In the months that follow, Quint and Beth slowly rekindle their romance — meanwhile, the German V-weapon program continues to advance, and they are getting ready to unveil the V-3. Quint is given the task of destroying the V-weapon plant at Charlon, a mission made possible by a new "bouncing bomb" called the "highball," invented by Dr. Barnes Wallis (of "Dambusters" fame). Just before the mission is to be undertaken, however, the Germans drop a film showing air prisoners, including a still-alive Scott, being moved to Charlon. Now the Mosquito crews will be killing their own colleagues and friends, and Quint must carry out his orders, which include hiding the fact that Scott is alive from Beth. The secret gets out to the squadron pilots, however, and a rebellion starts brewing in their ranks. Try as he might to find a way to save the lives of the prisoners, there seems to be no way for Munroe to avoid killing British pilots with British bombs.