“It's an awfully long time since Sister Joan found a dead body.”

These are the words of old Sister Gabrielle, but she may have spoken too soon . . .

There is clearly something weird going on in their quiet corner of Cornwall. There's been some obscene vandalism in the kitchen. A dog is kidnapped. And when a cat is killed, Joan knows there's evil afoot.

Then Sister Joan goes to visit Mrs Pearson. She's met with a horrifying scene.

Are these crimes just practical jokes gone horribly wrong? Or does someone have a dangerous obsession with the occult?

Sister Joan teams up with Detective Sergeant Mill to get to the bottom of things. But can they stop anyone else getting hurt?