Kate Tarleton grows up on a Southern plantation and becomes engaged to her guardian, Dr. Robert Manning, a famous surgeon. When Robert, Kate, and her younger sister Mary Lou visit New York, where the doctor wishes to conduct medical experiments, the superstitious Kate goes to the home of a fortune-teller named Stella Hill. Stella, whose principal business is white slave trafficking, drugs Kate and forces her to work in a "den of vice," run by Stella and her accomplice Jimmy Bristol, where she contracts syphilis and goes insane. Robert, Detective Ellis, and a lawyer named Billy Meredith rescue Kate, who recovers her sanity but remembers nothing of her bondage.

A former Annapolis cadet is thrown out of the Naval Academy for cheating on an exam. Of course he was framed, but he must enlist in the Navy to clear himself. Meanwhile he and his sweetheart search for a buried treasure on Lost Island, which everyone is after.