When a mysterious letter written in code arrives at King's house for his human, Kayla, he follows the trail of the person who left it.

"When a neighbor calls about ghostly noises in her attic, Kaz and Claire agree to investigate. Could that very familiar-looking ghost dog Kaz sees through the attic window be his lost dog, Cosmo? Venturing outside could be dangerous, but Kaz has to find a way to be reunited with Cosmo before he loses him for good."--

When King's favorite blue ball goes missing, he and Kayla must put together clues to figure out where it went.

When therapy dog Buddy attends the fourth grade sleepover in the school's library, he solves the mystery of the school ghost.

Soon after Claire is called on to investigate a new case, her ghostly partner Kaz is reunited with his brother, Little John, who joins them in searching for the cause of strange phenomena that occur each afternoon at five o'clock.

Dog-and-human detective duo, King and Kayla, must try to figure out how Raj's cat escaped from a locked house.

While attending obedience class with his new humans, Buddy the dog helps solve a mystery involving two Pomeranians that were switched at the dog park.

When Buddy goes to school to become a therapy dog, he ends up helping figure out who pulled the fire alarm instead.

A group of girls in Claire’s town have noticed strange sights and sounds coming from the tree house where their club meets. Is it a rival boys’ club trying to scare them away? Or is it a ghost? The girls ask Claire to tackle the mystery--and Kaz hopes to finally find the rest of his missing family members!