It's spring 1941, and Great Britain is the only country in Europe yet to be defeated by the Nazi army, but all of that could change soon. The Nazis have launched their juggernaut battleship, the Bismarck, to close off British supply lines and ultimately invade England. A counterstrike is ordered, and with an arsenal of ships at their command, Royal intelligence officers Jonathan Shepard (Kenneth More) and Anne Davis (Dana Wynter) fight desperately to distroy the Bismarck.