With the help of Professor Litefoot, the Doctor investigates the gruesome murder of a cabbie and the mysterious disappearances of young girls. Whilst being chased by giant rats and forced to pit his wits against an evil doll and a merciless illusionist, he comes face to face with his most deadly enemy to date: Magnus Greel - a fifty-first century war criminal posing as Weng Chiang, an ancient Chinese god. Can the Doctor thwart his dastardly plans before Leela becomes his next victim?