When her husband is wrongly accused of murder, an opera singer sets out to find the real culprit.

During the last half of the 19th century writer Richard Darrell saves Don Carlos from two robbers, and is entrusted by Don Carlos to take a valuable necklace to Spain. Richard leaves his fiancé, Oriana, and starts the trip. He meets Wycroft, a henchman for Sir Francis Castteldow, an aristocrat out to steal Oriana from Richard. The latter is assaulted, robbed and nearly killed and, as a result, loses his memory. He marries a gypsy girl, Rosal, while Oriana, thinking him dead marries the dastardly Sir Francis. Everybody will meet again. Complications will arise.

With the ending of the Spanish Civil War, a dispirited band of volunteers from the International Brigades seeks refuge in France. But on reaching the frontier, the band is disarmed, and all are detained as political prisoners. Then come instructions from Vichy that all fit prisoners are to be sent to Morocco to work on the Sahara railway for the Germans. However, one man manages to escape to London with vital information for the Allies.