After learning about Sherlock Holmes, Humphrey the classroom hamster follows clues to try to discover why Mrs. Brisbane is gone and Mr. E, a fun but not very educational substitute, is taking her place in Room 26 at Longfellow School.

While on field trips the kids of Franklin Middle School solve various crimes, including such mysteries as a museum painting that is really a copy, missing ticket money for a frontier town, recycling machines being shut down, and missing endangered foxes.

Young Sherlock finds comfort studying the world around him and reconstructing events, but when he decides to snoop around for clues to solve a sensational murder, Sherlock is accused of the crime and now must use all his mystery-solving clues to save himself.

While visiting Scrub Brush, a frontier town, with their teacher, Edward "Egg" Garrison and his friends are told that someone is stealing the ticket money which could force the village to close and they set out to find the culprit.

Scooby and the gang are enjoying a trip to Hawaii when a spooky witch doctor begins to make trouble. Can they solve the msytery of the haunted volcano?

In 1908, eleven-year-old Innie joins the library club at a settlement house that serves immigrant families of Boston's North End, but when items and money disappear from the settlement house, Innie's past as a troublemaker puts her under suspicion.

When the animal shelter where Nancy volunteers mysteriously burns down, Nancy and her friends decide to raise money to rebuild it by organizing a rock concert, but somebody keeps trying to foil their plans.

Just as her mother is about to give birth, Cam Jansen, along with her best friend Eric, while in the waiting room, discover that their camera is missing and must race against time to find it before her Valentine's Day sibling is born.

Answering tricky reference questions is excitement enough for library director Lindsey Norris, until a murder is committed in her cozy hometown of Briar Creek, Connecticut. The question of who did it must be answered before someone else is checked out--for good.

It's early October, time for the Fall Folk Art Festival and Bake Sale in Lilyvale, Arkansas. Every business along the town square will benefit from the event, including the craft store run by Leslee Stanton Nix--aka Nixy--and the Silver Six, a group of retirees. In charge of making the festival go smoothly, Nixy is confident that it will be a success. But things become knotty when local troublemaker Cornell Lewis is found dead with a plate of Snickerdoodles...