In May of 1941, noted newscaster Edward R. Murrow broadcasts a paean to the spirit of the British people as they are valiantly trying to stop the spread of Nazism throughout Europe. The course of the war, and thus the future of the world, depends on the Battle of the North Atlantic, which is being directed from the Admiralty Building in London, the central nervous system of the British Navy. When Capt. Jonathan Shepard, the recently appointed director of the operation, assumes command, he insists on strict adherence to regulations, disgruntling many of the old timers. After word comes that the Bismarck , the fearsome, most powerful German battleship afloat, may have been spotted off the coast of Norway, Shepard and the First Sea Lord scramble to pinpoint the behemoth's location before it can break out into the Atlantic. Meanwhile, as the Bismarck pulls up anchor from its hiding place in the Nazi-occupied port of Bergen, Norway to begin its voyage into the Atlantic, the German Fleet Commander sings the ship's praises as the symbol of the glory of the Third Reich. In a desperate race to stop the Bismarck , Shepard dispatches the battleship Prince of Wales , even though its crew is green and civilians who have been refitting the vessel at the shipyard are still aboard. When the Bismarck and its escort is spotted in the Denmark Straits, Shepard instructs the Prince of Wales to attack at dawn. In London, meanwhile, the Aide to the Sea Lord, an old friend of Shepard's, counsuls Lt. Anna Davis, the WREN officer serving as Shepard's aide, to have compassion for her superior, who lost his ship the previous year and whose son is presently serving at sea. As dawn nears, tension mounts aboard the Prince of Wales , which is joined by the warship Hood , the pride of the British navy. As the ships clash, the Bismarck outguns the Hood , sending it plummeting in flames to the bottom of the sea. Badly damaged in the attack, the Prince of Wales turns back, leaving the Bismarck unimpaired to roam the high seas. Realizing that the Bismarck 's' fuel line has been hit, the ship's captain, Lindemann, recommends putting in for repairs but is overruled by the admiral, who, intent on seeking greater victories, pushes forward. When word of the Hood 's demise reaches England, Winston Churchill orders that all risks must be overridden in the quest to sink the Bismarck . In desperation, Shepard strips the western Mediterranean of its ships, thus sending his own son, who is serving there, into battle against the deadly Bismarck . After the Bismarck 's escort departs, British flyers spot the battleship and drop a series of bombs, barely hitting the ship. To throw off the trailing British cruisers, the admiral orders the Bismarck to assume a zigzag pattern, thus losing their pursuers. Sensing that the admiral, in his quest to prove German superiority, will head for France rather than return home to Germany, Shepard deduces that the warship is headed for Brest, a Nazi-occupied city, and sends the aircraft carrier on which his son is stationed to the area. When word comes that his son's plane is missing, Shepard painfully recalls the day he returned home from sea to find his house shelled and learn that his wife was killed. Shepard then grimly states the incident made him determined never to become attached to anyone again. Anna, who lost her fiancé in war, commiserates and then accepts Shepard's offer to become his assistant, even though it means forgoing a lucrative promotion. Once the Bismarck is again sighted, Shepard dispatches the British warship King George to attack and then orders an air strike to prevent the German ship from reaching friendly waters until the King George can reach it. Her rudder damaged by the aerial bombs, the Bismarck is crippled. As the German admiral delivers an inspirational speech to his crew, the King George , accompanied by its cruiser, fires a deadly salvo at the Bismarck . Meanwhile, at British headquarters, Shepard sobs in relief at word that his son has been rescued at sea. Raked by torpedoes and gunfire, the Bismarck is doomed, but the delusional admiral promises the crew that the führer will save them, then dies holding a congratulatory telegram from Hitler. Amid the chaos onboard, Capt. Lindemann gives the order to abandon ship, and finally, the Bismarck sinks in flames. When news of the victory reaches London, Shepard invites Anna to a celebratory dinner, and they emerge from endless days shut away in their cramped offices into the daylight.