John Mayo, of the secret Government Department codenamed Operation Werewolf, loses his wife of only a few years, and heads away from the memories to recover his wits. He ends up in the Welsh town of Knighton which has recently come to grips with the graffiti and terrorism of Welsh National Activists, as well as a number of mysterious deaths seemingly through vampirism. Mayo believes he sees his dead wife among the vampires, and investigates. As the death toll mounts and the plot complicates, he fights his way to the bottom of the whole affair to find that all the different strands of trouble actually stem from the same place.