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.

About the Author
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.

Reviews
PRAISE FOR YOUNG CAM JANSEN AND THE KNOCK-KNOCK MYSTERY:

"The stories in the this series promote logical thinking and helpfulness for young readers beginning to enjoy simple transitional chapter books." -School Library Journal



Book Information
ISBN 9780142422250
Author David A. Adler
Format Paperback
Page Count 32
Imprint Penguin Young Readers
Publisher Penguin Putnam Inc
Weight(grams) 91g
Dimensions(mm) 229mm * 152mm * 4mm