By August 1914 the dreadnought battleship sits at the peak of its power, and the North Sea becomes the proving ground for the two largest navies on earth. The film opens with the British raid on Heligoland Bight, where Rear-Admiral Sir David Beatty pushes his battle cruisers into mined, torpedo-heavy waters against a potentially superior force and sinks four German ships at a cost of roughly a thousand German sailors. It builds to the Battle of Jutland in May 1916, when Admiral Jellicoe's Grand Fleet meets Admiral Scheer's High Seas Fleet head on, the first and largest clash of capital ships between the two powers. Both sides claim victory, and the losses run heavy on each: Britain loses more ships and more men, yet keeps command of the North Sea, and the German fleet never challenges it again. The film lays out the ships, the commanders, and the tactics behind both engagements, and leaves the still-unsettled argument over who actually won Jutland open for the viewer to weigh.