The Creeping Flesh
1973

After a long journey overseas to Papua New Guinea, Professor Emmanuel Hildern returns to England with the skeleton of what he hopes is a missing link that will radically alter our understanding of man's origins.

While cleaning the skeleton's hand, he notices that water allows flesh to form over the bone. He cuts off the fully-formed finger and places the swollen digit in a specimen jar.

Puzzled by this he goes to his library to do some research. He uncovers references to 'The Evil One', an ancient god that will be awakened by a deluge.

As he examines the blood taken from the flesh of the creature, he realises that it contains pure evil. He has the idea that he may be able to develop a vaccine from its blood to inoculate against evil and bring about a new age of peace. His first guinea pig is his own daughter, Penelope, who is showing the first signs of madness that sent her mother to the asylum. Injecting her with the serum, it has the opposite effect wanted, and she turns into a murderer.

This draws the attention of Emanuel's half-brother James, who runs the asylum his wife was sent to. He's also busy tracking down an escaped lunatic of his own.