Dori Hillestad Butler has published magazine stories, educational materials, plays, book reviews, characters for a board game, and over sixty children's books. A two-time Geisel Honor Book winner for King & Kayla and the Case of the Missing Dog Treats and King & Kayla and the Case of the Lost Tooth, she has also been nominated for children's choice awards in nineteen different states and won the 2011 Edgar Award for the best juvenile mystery for Buddy Files: Case of the Lost Boy. She lives in Washington.

A lovable dog helps his human girl solve a mystery.Kayla and Mason both got mysterious letters, written in code. What does Kayla know? ¿The same person left both letters. It's someone she and Mason both know. The two letters are the same, except for the second word.What does King know? ¿Jillian left the letters. What do the letters say?