Three young detectives travel abroad to solve a mystery involving a silver spider and a political plot that endangers the life of a young prince.

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

A wallet dropped by a scar-faced beggar sets the three investigators on the trail of bank robbers.

The three investigators, attempting to rescue a beached whale, end up searching for sunken treasure.

When an eccentric local artist disappears suddenly, the three investigators look into the matter.

While accompanying Pete's inventor grandfather to New York where the old man plans to sell his new invention, the Three Investigators find themselves in the middle of a dangerous spy case.

The Three Investigators become entangled in the theft of a string of rare pearls and a fraudulent scheme involving family inheritance when they try to solve the mystery of a ghost's appearance in the old Green Mansion.

The Three Investigators search for an authentic haunted house.