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.

While learning detective skills at summer camp, Dink, Josh, and Ruth Rose undercover a real mystery involving stolen paintings. Includes a hidden message.

Bradley, Brian, Nate, and Lucy follow clues on an Easter treasure hunt, while trying to figure out who set it up for them.

When someone steals the money the town has been collecting to help the ducks, Josh and his friends try to find the thief.

KC and Marshall investigate the theft of a precious emerald, brought by representatives of the Chinese government to bring luck to two baby tigers born at the National Zoo.

"Mr. Paskey, owner of the Book Nook, plays an April Fools' Day prank on Dink, Josh, and Ruth Rose. They hatch a plan to get back at him, but then the bookstore is robbed--no joke! Can the kids track down the crook? Or will this April Fools' be an April fail?"--

"It's sleepover night at the children's museum. Dink, Josh, and Ruth Rose can't wait to see the museum's colossal fossil--a giant Spinosaurus skeleton--and tour the exhibits long past closing time. But later, they wake to a terrible crash! Is the dinosaur fossil damaged? Or is there another big problem at the museum?"--

Bradley, Brian, Nate, and Lucy follow clues to find whoever left a rabbit in their first-grade classroom on Valentine's Day, because they are worried the rabbit will get sick and die of loneliness.

KC and her friend Marshall decide to do a little sleuthing of their own when KC's mom and the clone of the president of the United States are kidnapped by disgruntled astronauts who want to take over the International Space Station.

KC discovers that the President of the United States has been replaced by a clone and sets out with her friend Marshall on a dangerous mission to set things right.