"The Mystery of the Sea" by Bram Stoker is a mystery novel published in 1902. An Englishman in Scotland encounters an American heiress entangled in the Spanish–American War's dangerous intrigues. Their romance unfolds amid supernatural visions, kidnapping plots, and encrypted secrets linking sixteenth-century Spanish treasure to contemporary political conflict. Blending second sight with espionage, Stoker crafts a political thriller that weaves historical events across centuries, exploring national identity and evolving ideas of womanhood in this overlooked companion to his famous "Dracula."