The body of an old man is found floating in the Thames ­ although the DNA of the corpse corresponds to an 18-year old friend of Josh and Ellie. Sarah Jane heads towards West Yorkshire in a bid to discover what killed the man, why someone is kidnapping homeless teenage boys and whether there is a link between that and the retreat of philanthropist Will Butley which hosts The Huang Ti Clinic. Sarah discovers that there is more to ancient Dark Sorcery than she may have otherwise believed.