Cam, her best friend Eric, and Eric's mom are spending the day with Eric's grandparents. But Grandpa and Grandma seem too tired to visit. Every so often, a knock at the door wakes them up. But when they go to answer, no one is there. Is a Knock, Knock Ghost on the loose? It's up to Cam to solve the mystery! Garden State Children's Book Award 2017 Nominee.
Author Biography
David A. Adler is the author of over two hundred children's books. He lives in Woodmere, New York. Susanna Natti also illustrates the Lionel series by Stephen Krensky. She lives in Bedford, Massachusetts.
