Kieron Moore stars as research scientist Dr. Peter Blood, who's been experimenting with heart transplants. Thrown out of Vienna for wishing to move from lab animals to humans, Blood sets up shop in the village of Cornwall. Within a few months of his arrival, several Cornwallians disappear from view. Dr. Blood, you see, has been merrily transplanting hearts in a secret lab located in an abandoned tin mine. Unfortunately, one of his resurrected humans reacts negatively to the operation - especially after he discovers that Blood has been dallying with his wife.