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 Aldens investigate when an old wooden mask they have found is stolen.

Caroline is thrilled when her cousin Lydia and friend Rhonda stay at her house for the winter, but she begins to reconsider when Rhonda and Lydia spend all of their time together without Caroline.

When Caroline visits her uncle Aaron's new farm, she keeps watch when a thief starts sneaking around the farm, and discovers that some things are not as simple as they seem.

When their favorite author fails to arrive as scheduled to speak at the local library, the Alden children investigate how he could board a train and never be seen again.

The Boxcar children must track down an instrument thief in time to save Greenfield's music festival from disaster.

While spending two days touring a zoo to see the baby animals, the four Alden children, aged six to fourteen, help catch an escaped monkey, participate in a photography contest, and investigate a missing camera.

While visiting the Diamond Drive-In with their grandfather, the Boxcar Children investigate a series of pranks and ghost sightings at the outdoor theater.

Encyclopedia Brown, boy detective extraordinaire, solves ten new cases, including "The Case of the Miracle Pill," "The Case of Nemo's Tuba," "The Case of the Lawn Mower Races," and "The Case of the Air Guitar." Solutions provided at the end of each chapter.

The Aldens help out at a minor league stadium and investigate when it appears someone in the ballpark is stealing the home team pitcher's signals and relaying them to the batters of the other team.