What seems to be a man eating tiger on the loose is actually the first step in a plan to take over the whole of England.
Sir David Harper, owner of an experimental livestock farm, is killed, apparently mauled by a tiger and when three other men die in the same way Steed finds a link to P. U. R. R. R. , a cats charity of which all the victims were board members and discovers a plot to turn the domestic felines of the country into vicious killers.—don @ minifie-1