What Dwells Beneath the Waves by Robbie Dorman

Deep below the water, something waits.

Journalist Moira Bell is in the Florida Keys to cover climate change, but her investigation soon reveals a series of unreported disappearances on Blackwell Key. Disappearances noteworthy only because the missing people always come back.

Come back as something else.

Moira ties the disappearances to Butch Blackwell, chief of police and direct descendant of the original settler of Blackwell Key. He’s hiding something on his private island, just offshore. With a massive hurricane approaching, Moira has little time.

When Moira sneaks her way onto his island, she finds a dark obelisk. A bloody ritual. Worship of something beyond our world. Something long asleep.

Moira must stop Butch before he awakens something that will undo the Earth.