Set in England during the early days of World War II, a Danish sea captain and his passenger are kidnapped by a cell of Nazi spies operating from a basement in London's Soho. The plot progresses as a chase that puts the characters in one peculiar set of surroundings after another. Most of the story takes place under blackout conditions, in which the great city becomes a mysterious dark labyrinth.

Originally produced as a motion picture in 1940. Also issued as part of the box set: Film noir, five classics from the studio vaults.