1876, Kamerun, West Africa: a German trading party stops on the outskirts of a tribal village. Their leader approaches it alone. Minutes later he stumbles back to them screaming, 'burn it down, burn it down, burn it down!'
1915, The North Sea: HMS Bowman finds the German submarine, U-31, adrift in the water. All of the crew are dead. Every corpse is hideously disfigured.
As millions of men settle into the trenches that are scarring the Western Front, Captain John Quintrell and his men are sent deep into Germany to find and destroy the horrific weapon that could change the course of World War One and alter the face of warfare forever.