What if there was something sinister swimming beneath the sea’s surface? Bristol Cove, a sleepy coastal town that legends say was once home to mermaids, is about to find out. A mysterious and otherworldly girl is wreaking havoc in Bristol Cove, and marine biologists Ben and Maddie must work together to find out who she is and what she wants. Could she be a mermaid, a primal hunter of the deep sea driven to land? And if so, are there more like her out there?