King & Kayla and the Case of the Secret Code - Dori Hillestad Butler

The first in a new series featuring King, a lovable dog who helps his girl Kayla solve the mystery of who sent letters, written in code, to Kayla and her friend, Mason. Full color. nA lovable dog helps his human girl solve a mystery. nKayla 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?