A number of packaged disembodied heads have been in random areas of the English countryside. In each package is a letter to the police from the killer, who dubs himself "The Executioner." Each victim is seemingly unrelated to one another. When a Scotland Yard employee is killed, Detective Mike Brixan (Heinz Drache) of Special Branch is called in to investigate. The only clue is that a black, four-door sedan has been seen at the scene of the crime, and that the typewriter that the letters have been written on have two offset letters.