The Tomb of the Sea Witch - Beaumont and Beasley, #2

Something is stirring in the deep. Searching for a cure for his curse, detective-turned-monster Nick Beasley has traveled to Warrengate Academy, a mysterious school for wizards. He, the enchantress Lady Cordelia Beaumont, and Nick's brother Crispin go undercover to access the school's resources of powerful magic. However, an ancient power from deep beneath the sea has taken notice of Nick and his companions, and soon ensnares them in a terrifying plot for revenge.
Stories are history in the Afterlands, but the true story of the Little Mermaid has never been revealed.until now. Can Nick, Cordelia, and Crispin overcome the rising darkness before it drowns everything they hold dear?