After Tara Hayes's most recent best seller, she and her long-time girlfriend Wendy go on a road trip. They soon arrive along the Florida coastline at the Sacred Isle Diner where yet another case falls onto Tara's lap. She uses her training as a PI and the notoriety from her famous book to wedge her way into the investigation of a man who appears to have been killed by a mermaid. Though Tara knows the idea is ridiculous, the possible siren that haunts the Florida coastline is all she can think about. It's not long before Tara stumbles on Sabrina Taylor, the victim's sister and forgets about Wendy entirely.  Sabrina is a blonde bombshell with an amazing voice and even more amazing touch. Tara is enchanted right away, but a shocking turn in the investigation makes her realize that Sabrina may be more than who she says she is.