John Chandagnac is a puppeteer traveling to Jamaica to confront an uncle he has never met. John’s father died alone and in poverty, indirectly because his brother (John’s uncle) stole his inheritance. John, however, owns a share of the guilt for his father’s death.
John runs afoul of pirates, followers of the infamous Blackbeard (Thatch), and is forced to join their band. Thatch and many of his associates are sorcerers, employing the techniques of vodun (voodoo) for protection and other purposes. One of these men, the Oxford don Benjamin Hurwood, intends to perform a difficult magical rite, using his daughter Elizabeth as his unwilling subject. Hurwood’s sadistic assistant, Leo Friend, has obsessions of his own that clearly involve Beth. Chandagnac, called Jack Shandy by the pirates, falls in love with Beth and decides to rescue her if he can.
A chase in search of her leads him into the ghost-infested swamps of southern Florida, where fungi sneeze ghost seeds and the jungle itself is an enemy. Thatch and his associates are headed for the Fountain of Youth, a center of great magical power. Once there, Thatch, Hurwood, and Friend perform a magical procedure that confers a limited immortality. Hurwood and Friend also complete the initial phase of the procedure by which they plan to evict Beth from her body and replace her soul with that of her dead mother.
Shortly after his nearly disastrous return from the Fountain of Youth to the Florida coast, Chandagnac loses Beth, first to Friend and then to Hurwood. After a period of drunken denial, interrupted by a failed attempt to recover his inheritance, Chandagnac makes one last desperate attempt to find Beth and rescue her. A chance meeting with one of the most powerful voodoo deities, the loa Mate-Care-For (Maître Carrefour, the Master of the Crossroads) is the catalyst that makes him realize that life is meaningless without Beth. Ultimately, he must fight both Thatch and her father for her, armed with scarcely more than his wits. Chandagnac’s growing understanding of the nature of voodoo, combined with Beth’s strength and loyalty, enables him to sever Thatch’s link to his powerful mentor, the sinister loa of graveyards, Baron Samedi.