Third-grader Dink and his detective friends hope to receive a big reward by finding the person whose video recorder picked up a picture of the local bank robber.
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.
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.
When Dink, Josh, and Ruth Rose visit a dude ranch in Montana, they find themselves with another mystery to solve, this one involving the theft of money from the ranch's safe and of a large gold nugget that Josh had found.
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.
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.
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.
