Swashbuckling historical drama starring Flora Robson, Laurence Olivier and Vivien Leigh. In 1587, the court of Queen Elizabeth I (Robson) is a hotbed of intrigue, espionage and danger. Young naval officer Michael Ingolby (Olivier) is appointed by the Queen to go undercover and infiltrate the court of Philip of Spain to discover the names of the traitors who plot her death. His daring feats earn Ingolby the love of English courtesan Lady Cynthia (Leigh), Spanish noblewoman Elena (Tamara Desni) and Queen Elizabeth herself as he leads the British fleet into battle against the Spanish Armada.