A thrilling new case for London’s most talented psychic detection agency – from the global bestselling author of the Bartimaeus Sequence. In London, a mysterious and potentially deadly ghost is stalking the halls of St Simeon’s Academy for Talented Youngsters. It lurks in the shadows, spreading fear and icy cold – and it carries a sharp and very solid dagger… The headmaster wastes no time in enlisting the help of ghost-hunters Anthony Lockwood, Lucy Carlyle and George Cubbins. Can Lockwood & Co. survive the night and save the day?

After leaving Lockwood & Co. at the end of *The Hollow Boy,* Lucy is a freelance operative, hiring herself out to agencies that value her ever-improving skills. One day she is pleasantly surprised by a visit from Lockwood, who tells her he needs a good Listener for a tough assignment. Penelope Fittes, the leader of the giant Fittes Agency wants them--and only them--to locate and remove the Source for the legendary Brixton Cannibal. They succeed in their very dangerous task, but tensions remain high between Lucy and the other agents. Even the skull in the jar talks to her like a jilted lover. What will it take to reunite the team? Black marketeers, an informant ghost, a Spirit Cape that transports the wearer, and mysteries involving Steve Rotwell and Penelope Fittes just may do the trick. But, in a shocking cliffhanger ending, the team learns that someone has been manipulating them all along