Alfred Hitchcock mystery series

An old trunk involves the three investigators with dangerous criminals seeking a cache of stolen money.

Hired to discover why a wild-animal farm's tame lion has become unpredictably nervous, three young detectives begin an investigation that uncovers a smuggling operation.

Three young sleuths uncover a coven of witches when they search for the missing memoirs of a movie star.

The theft of some mutant army ants by a scarecrow leads the Three Investigators to the solution of two daring crimes in the art world.