When Dink, Josh, and Ruth Rose visit Washington, D.C., just before Christmas, they are inadvertently caught up in a kidnapping plot that was intended for the president's dog, but also involves the president's stepdaughter and her friend Marshall.

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.

KC and her friend Marshall accompany KC's stepfather, the United States President, to remote Camp David, where they find clues that point to either ghostly or criminal activity.

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

When three leprechaun statues disappear just before St. Patrick's Day, Bradley, Brian, Nate, Lucy, and other friends follow clues in order to prove that Lucky O'Leary is innocent of the crime.

When the guests of the Shangri-La Hotel are scared away by a white-haired female ghost, Dink and his friends investigate the mystery.

Josh and his two friends look for the person who stole a peregrine falcon from its nest.

Dink and his friends unearth the mysterious truth behind the envelopes incorrectly delivered to his house.

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

Dink and his friends investigate why pets, like Mrs. Davis's canary, Mozart, are mysteriously disappearing all over town.