Hoppy and Lucky have been called in to investigate a series of stage holdups. The robbers are taking gold from Colby's mine and Hoppy suspects it may be ex-outlaw Colby himself.
A dizzy young woman aranges to turn her inventor-boyfriend's vacation into a chance meeting with a possible investor who happens to be her brother's future father-in-law.
In 1830 Pierre Courier, a rich and elderly shipowner, awaits the return of his son Stefano, who has just returned from a long trip to Trinidad in the ship in which he is captain.
Grace Peterson works in department stores "Tutto per Tutti", along with many other young people. His employment contract entitling them to live in a boarding house built specifically for them by the company but on the other hand, forbid them not fall in love or marry under threat of dismissal.
A gang of urban street kids and a club of suburban would-be federal agents, at first rivals, join forces to rescue the father of one of the kids, the inventor of a super-explosive and its remote detonator, from the clutches of a band of foreign subversives call the "Flaming Torch Gang".