The Welsh hills are beautiful by day, attracting visitors from miles away. But at night an uneasy silence reigns, and in the gathering mist and darkness lurk the ancient evils. The people of the village near the Black Hill shunned the night. Only the shepherds stayed out to guard their flocks. Till one night, when a sheep was found savagely mangled. The old men muttered of the 'Black Dogs', harbingers of death, while the young men laughed uneasily. Not only were animals in danger but the young women too. Soon no-one dared go out at night, for the danger that threatened was more fearful than anyone imagined. When the moon was full, the shape of half man half wolf was seen on those hills...

The Black Hill werewolf, Philip Owen, has been dead for a year, and there have been no further outrages. Until now, that is, and the new maulings coincide with the disappearance from his grave of Philip Owen's body. Gordon Hall, the man who caught Owen a year before, returns to the Black Hill to help with the search, and when Owen's body is found, he realises that there is a new werewolf loose.

Margaret Gunn, raped by a psycho in a wolf's costume in Return of the Werewolf, gives birth to an unusually ugly child. He grows up to become a loner, a bully and finally a murderer, as he slices up his headteacher at the age of fifteen. While in gaol he discovers he is a werewolf and on his release the murders start again.