Aileen Donovan is an oceanographer with magical control over the element of water. While her normal focus is on research and fighting poachers, she's about to go up against the stuff of legends-and that's saying something for a supernatural.

A transport ship is missing and everyone's eager to get their hands on the cargo. No one knows what exactly it is, but when fragments resembling coral begin to drive local residents insane, Aileen suspects a preternatural source. Whatever is at the bottom of the ocean, a power-hungry alchemist wants it, and releases a sea dragon to eat the competition-literally.

Aileen sees this as an opportunity to win the professional recognition she desires, but keeping secrets is complicated when she's working with local Coast Guard officer Colin Benson. Her sense of love and duty will be put to the test, and when the tide washes out, it might have been better if that lost ship had stayed lost.