Cecil Dreeme, Theodore Winthrop's most important work, was a semi-autobiographical novel. The gothic tale features a young traveler, Robert Byng, who returns from abroad to New York. He lodges in an impressive building along with other young Bohemians and artists, including a mysterious and alluring painter, with whom he strikes up a friendship. Both of them must avoid the sinister machinations of millionaire tycoon Densdeth, who also has a dark store room in the building.