The Camp Knock Knock mystery /
Betsy Duffey ; illustrated by Fiona Dunbar.
- New York : Doubleday Book for Young Readers, c1997.
- 46 p. : col. ill. ; 20 cm.
"A Yearling first choice chapter book." Sequel to: Camp Knock Knock.
If Willie would change into clean clothes while at summer camp, he may find the joke book which Crow has hidden from him.