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

When her best toy mysteriously disappears, Olivia the feisty pig is determined to find out who is responsible.

Someone lost a camera, and Franklin found it. Is it "finders keepers," or should Franklin try to find the owner?

Thor's hammer is missing again. The thunder god has a disturbing habit of misplacing his weapon--the mightiest force in the Nine Worlds. But this time the hammer isn't just lost, it has fallen into enemy hands. If Magnus Chase and his friends can't retrieve the hammer quickly, the mortal worlds will be defenseless against an onslaught of giants. Ragnarok will begin. The Nine Worlds will burn. Unfortunately, the only person who can broker a deal for...

On the night before Christmas, Olivia discovers that her favorite stuffed monkey, Mathilda, is missing, as are other favorite items from around the house.

Discovering a smelly creature in her garbage can that she names after herself, Olga befriends and studies the eccentric Olgamus using the scientific method, the practices of Jane Goodall, and other scientific concepts.

When they are separated for the first time since birth, Iris and Lark struggle with insecurities over their individual identities at the same time things begin to go missing around town.

Joey Pignattano made a Halloween bet. He is going to eat a worm for a dollar. The only problem is, someone stole the worm. And the number one suspect is a mummy! It's going to take two top detectives like Jigsaw and Mila to unwrap this ooey-gooey mystery.

Morgie accuses his best friend of taking his favorite dinosaur toy without asking, and then he finds that he must apologize.

When a puppy who is being trained as a police dog goes missing, third-grader Judy forms a detective agency to solve the mystery, imitating her literary heroine, Nancy Drew.