Oliver Holmes and the Mystery of the Purple Possum in Bloomington, MN

A high school janitor. An old security dog. And a museum murder with a twist.
Oliver Holmes is summoned to help the police solve a case in which an old security dog is the only witness to murders in a museum. When nothing appears to have been taken, clues unite this crime to the previous one, creating dangerous conditions in which no one is safe. Can Oliver protect his loved ones while solving a mystery that is far different from what it appears?