Four dead bodies are found in a Soho studio, they were of : a former body builder, a studying actress and a photographer and his assistant. Perry Trethowan of London's C.I.D. was unable to find a link or any reason for these murders to have occurred, yet he has to go deeper into the investigation. He finds himself quickly caught up in a sordid world of a competitive body builder. He employs a black gym manager to work undercover and Trethowan investigated further into the case - yet the investigations progress seems to hinder and what he does discover seems unikley.