killer protects kid

A 12-year-old orphan who has just inherited a fortune is trapped on an island with his uncle, a former British intelligence commander who intends to kill him. A young girl is the boy's only ally against the sarcastic uncle, who uses hypnotism, a pool of sharks, fire, and poisonous mushrooms as weapons.

Children are being kidnapped and held for ransom. If the parents don't cooperate, the kids show up dead. An undercover cop gets involved in the case, and his investigation leads him to a connection between a banker and a fortune teller.