Riptide

Riptide is a 1998 thriller novel published by Tor Books. The standalone story is the fourth full-length Preston-Child collaboration.

Plot Summary
"In 1695, a notorious English pirate buried his bounty in a maze of booby-trapped tunnels on an island off the coast of Maine. In three hundred years, no one has breached this cursed and rocky fortress. Now a treasure hunter and his high-tech, million-dollar recovery team embark on the perfect operation to unlock the labyrinth's mysteries. First the computers fail. Then crewmen begin to die. The island has guarded its secrets for centuries, and it isn't letting them go—without a fight."-Publisher's synopsis

Continuity

 * Riptide is the only Preston-Child novel to not have any of its characters reappear in another book.
 * In The Cabinet of Curiosities, while searching the Central Archives at the museum, Nora Kelly comes across late 19th-century correspondence from a herpetologist from Riptide 's fictional town of Stormhaven.