S01E01 The Grey Wolves
New testimony from British sailors and the U-boat men who hunted them, plus archive material and dramatic reconstructions, illustrate the threat from Churchill's one fear, the hidden enemy under the sea.
In the first 18 months of war, German U-boats sank more than three million tons of shipping. Eyewitness testimony, archive film and reconstructions illuminate the story of how Allied intelligence fought back against the killers in the deep, helped by the seizure of an Enigma code machine and cipher material.
Explores the desperate struggle for survival on a hostile ocean during the longest and bloodiest battle of the Second World War.