When Kayla's tooth disappears before the Tooth Fairy has a chance to visit, her dog King helps her solve the mystery.

Trying to communicate with his human owner (and detective partner) can be frustrating for King the golden retriever as he uncovers clues in a missing dog case.

The Aldens realize the food their dog, Watch, is eating in a commercial and enjoying is not the same as what is being sold in stores, and must decide whether they should continue to allow him to work for the dishonest company.

Chip, an invisible boy, and his friends solve the mystery of who took the school ball from the playground.

The Aldens' dog, Watch, comes across a mysterious box with a note inside, a box that is part of a game called Geocaching. Henry, Jessie, Violet, and Benny join the game but soon suspect one of the members of the geocaching club is a thief.

When 7 is accused of eating 9, worried 6 hires a detective to investigate.

When the children uncover a strange puzzle in a friend's back yard, it's the start of a "spy game" leading to gold. But first they must make sense of an old photo and a riddle, and learn just who is behind this mystery within a mystery.

When someone breaks into Mama Tova's bakery and tries to steal her secret recipe, the Aldens must use their mystery-solving skills--and their taste buds--to solve the case.

When the Aldens have the chance to work at a candy factory, they try to find out who is sabotaging the candy and why.

Henry, Jessie, Violet, and Benny discover that some of the clues to the Great Detective Race are fake and set out to find out who is trying to ruin the race.