Sir James Forbes arrives in a remote Cornish village to identify a mysterious plague afflicting the population. Meanwhile, the local squire Charles Harris is using the voodoo magic to resurrect the dead to work in his decrepit and unsafe tin mines that are shunned by the local population. His magic relies on human sacrifice and he unleashes his army of the undead on the unsuspecting village with horrific consequences. When a strange illness claims the lives of the able-bodied young men in a Cornish village, all avenues of suspicion lead to the local Squire, owner of a disused mine. Living corpses carry dead bodies, graves are found empty, ritual voodoo ceremonies take place and specialist Sir James Forbes is hard put to prove the culprit. The culmination is a fiery Hell.