The Alden children stumble upon a mystery when they enter their dog, Watch, in a contest that could lead to fame and fortune, but where things keep going wrong.

The Boxcar Children have been choosen to compete against another team to look for clues on a game show.

When the Aldens agree to watch the house of a local author who has written a book about a vampire, they end up investigating activities that are suspiciously similar to those in his book.

The Aldens are excited to meet their favorite celebrity Walter the Cat, who makes the funniest videos on the Internet! And when this celebrity cat inherits a million dollars from his owner, he becomes even more famous! But someone seems to be angry about the will and is stealing things from Walter's house. Is this cat too famous for his own good?

The Boxcar children investigate when ice cream and other items start disappearing from their favorite ice cream parlor.

The Alden children plan to ride in their boxcar at the Greenfield Founders' Day Parade, but the newly refurbished boxcar is stolen a couple of days before the big event.

During a trip to Oregon, the Aldens are astonished when Watch discovers a backpack filled with valuables, a finding that compels them to learn what happened and return the backpack to its rightful owner.

While on a camping trip with their grandfather, the Alden children try to find out about the loud music and missing food that threatens to scare away other campers.

While visiting the seaport town of Ragged Cove, Massachusetts, the Alden children find the ship's log of the Flying Cloud, shipwrecked in 1869, supposedly during a mutiny.

When they take their dog, Watch, for obedience training, the Alden children discover that some of the dogs in the class have vanished and decide to try to solve the mystery of their disappearance.