For generations, the wizards of Candle Paranormal Investigations have helped the people of Boston with everything from garden-variety poltergeists to Eldritch abominations. Sixteen-year-old Henry Candle, however, has no interest in taking over the family business and would much rather spend time hanging out in cafes with his human friends. But when his father is brutally murdered while working on a case, Candle Paranormal Investigations magically falls into Henry's possession — and so does a warning: "BEWARE, HENRY. HE'LL COME FOR YOU, TOO."
Henry does some digging and discovers that two other wizards have been killed in the past month, both of their bodies found with the same symbol scrawled into their chest as his father. He decides to reopen the case so he can discover who (or what) is murdering Boston's wizards before he's next. Aided by his pug familiar, a witch and a group of human friends, Henry must stop a supernatural serial killer and find an evil spell book that could end the world.