In a German town long ago there was a Toothpuller's apprentice called Klaus. He didn't mean to get into trouble. It wasn't his fault that he happened to see the Toothpuller find a diamond in the tooth of a dead man in Frau Drecht's lodging house. And he couldn't help it that Frau Drecht and her murderous son wanted it for themselves, or that a Professor of Anatomy took such a strange interest in it, and he had nothing whatever to do with the Jesuit priest and his Aztec companion and sinister pet monkey who turned up out of nowhere looking for it too. No. Klaus didn't want any trouble. But unfortunately he found himself with the diamond in his pocket, and then there was trouble. But when the Feathered Man appeared, that's when it really became a matter of life and death.