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?