A coven of witches bent on murder, a cult of hidden figures raising a leviathan to smite the city … sounds like a regular Wednesday morning for Boston PD’s supernatural division.

Chloe Mayfield is a career cop, but when a high-profile bust goes spectacularly wrong, she finds herself assigned to the losers in Blue Moon …

… and discovers a world she never knew existed.

Tasked to investigate a drowning far from water in a high-rise building, the symbol carved into the victim’s chest defies explanation. Until she begins to pry, and a coven of witches show up with a threat to stay out of their business.

With a wise-cracking dwarf and a senior-citizen claiming to be a descendent of Joan of Arc at her side, she’ll need to uncover the truth and stop the killer. And she’d better do it soon, because the tides are rising, and one single misstep is all it will take to leave the city, not to mention her career, in ruins.