On October 14, 1939, a solitary German submarine stealthily glided into the theoretically impregnable naval fortress of Scapa Flow. In a short amount of time, right before it, lay dead in the water the iconic ship of the British navy, the battleship Royal Oak.

The well-aimed torpedoes fired directly into the hull of the ship filled the sky with huge flames, spreading panic and turning the naval fortress into a fiery hell. The German submarine submerged and escaped through the dark waters, unscathed and unnoticed.

In the book at hand, Günther Prien, the commander of U 47, details the planning and execution of this, the most daring naval operation of World War II. An operation that Winston Churchill himself referred to as: "A naval feat of incredible skill and courage."