An engineer (Richard Dix) leads the building of a trans-Atlantic tunnel linking Britain and the United States. A remake of the 1933 German film, DER TUNNEL.
The film is a historical drama set during the reign of Elizabeth I (Flora Robson), focusing on the English defeat of the Spanish Armada, whence the title. In 1588, relations between Spain and England are at the breaking point. With the support of Queen Elizabeth I, British sea raiders such as Sir Francis Drake regularly capture Spanish merchantmen bringing gold from the New World.