Dink, Josh, and Ruth Rose investigate the disappearance of a valuable racehorse that Dink's uncle and his friend, Forest Evans, have just bought and entered in a race at Saratoga.
While visiting their friend Wallis and her adopted daughter on Mount Desert Island, Maine, Josh, Dink, and Ruth Rose investigate why three white wolf cubs were stolen, and by whom.
Dink and his friends meet an exchange student, Sammi, who is actually the prince of an island country, hiding from those enemies who have kidnapped his parents and who may be after him as well.
While picnicking on Squaw Island, Dink, Josh, and Ruth Rose find a hundred dollar bill, and when they return to explore further they find an entire cave full of money.
When Ruth Rose and her friends, vacationing in Florida, discover that her grandmother is about to invest in a project to recover sunken treasure, they stumble upon evidence that the entire plan may be a fraud.
Reports of zombies and grave-robbers alarm the people of a Louisiana swampland village, but Ruth Rose, Josh, and Dink begin to suspect that the supernatural may not be the cause of the eerie occurrences.
When the umpire at the baseball game fundraiser is accused of stealing a collection of autographed baseballs, Dink, Josh, and Ruth Rose try to prove his innocence.
Dink, Josh, and Ruth Rose investigate the theft of a great deal of money from the belly of a nearly life-size Tyrannosaurus Rex model that their friend, Jud Wheat, is using to raise money for a dinosaur museum.