During the second world war, the Nazis looted everything they could get their hands on, including an estimated 600 tons of gold, thousands of pieces of artwork, and millions of priceless artifacts. While some of these items have been found, much of it remains missing. Treasure hunter Darrell Miklos believes some of these stolen riches were loaded into specially modified U-Boats that are currently lying at the bottom of the Caribbean Sea. His evidence: two top-secret documents acquired over 40 years of research.

From the beginning of the Second World War the sea became a vitally important scene of conflict. Great Britain relied on receiving supplies by sea and, therefore, a total blockade of the United Kingdom was one the main objectives of Hitler's Germany. The British government was forced to maintain a strategy of antisubmarine warfare throughout the conflict, while the Royal Navy sought to interrupt the Third Reich's maritime traffic. In these circumstances the submarine became an important weapon of war. Headed by Karl D nitz, who would later succeed Hitler as Head of State, the German U-boats gained the initiative in the sea war and from the beginning launched all-out attacks against shipping en route to Great Britain. One of the great unanswered questions of the war is what would have happened if Hitler had granted the numerous requests made by D nitz for more submarines?

Grey Wolves captures life on board a U-boat, from the German perspective. First hand accounts in text, letters, diaries, journals, memoirs, relaying tales of the mundane and the routine, dramatic and heroic; the fear and resilience of every crew member, from Kapitainleutnant to Mechaniker. It is a vivid, brutally realistic portrait of the men who fought and died beneath the surface of the Atlantic in what was, perhaps, the most critical battle of the war.