The 27th Day (1957)
Aliens take five people, give them small capsules which can kill mankind without additional damage, with the understanding they will colonize Earth only if they use the weapons
The Four Skulls of Jonathan Drake (1959)
Anthropologist Jonathan Drake believes that the men of his family have been cursed for generations by the native South American tribe he studies Shortly after his brother, discovers one of the tribes shrunken heads, hes found murd