Luke Harding's third thrilling case involves a series of mysterious murders in which the victims seem to have only one thing in common -- the same name, Emily Wonder. In the bitter cold of winter, the teenage forensic investigator and his robotic assistant, Malc, investigate the three crime scenes and struggle to identify the murder weapons used, as no traces have been left behind. When a young homeless girl named Emily Wonder is reported missing, Luke and Malc rush back to the slums of London to try to save her from the murderer—and from a giant tidal wave that threatens to destroy the city.