When his toothbrush goes missing, Dog's friends help him look for it.

Nate the Great solves the mystery of the missing picture.

As Nate the Great sets to work on his first international case, he searches for a lost "something" and saves the King of Sweden from a troublesome traveler.

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

When Pinkalicious and her friend Molly go to the Pinkville Fair, everything reminds Pinkalicious of Goldilicious and she starts to miss her unicorn. Fortunately, Pinkalicious appears with her own best friend, another unicorn.

King's human, Kayla, has baked some treats for a friend's new puppy, Thor, but some go missing and it is up to King to find the culprit.

When her doll Marabelle goes missing, Nancy and her friend Bree become sleuths to crack the case.

When a wolf cub and little girl are lost in a snowstorm they must find their way home.

"Third-grader Aven Green has been solving mysteries for a whole month, cracking such cases as The Mystery of the Cranky Mom. But can this perceptive detective solve two cases at the same time? First her teacher's lunch bag disappears. Then Aven's great-grandma's dog goes missing. Fortunately, since Aven was born without arms, all the "arm" cells went to her super-powered brain instead (that's her theory)."-- Publisher's description.

Nate the Great and his dog Sludge look for Annie's housekey which has mysteriously disappeared.