When Triangle breaks the rule about not hiding behind the waterfall while playing hide-and-seek with Circle and Square, Circle must rescue him.
Mac Barnettis the author of numerous books for children, including five illustrated by Jon Klassen:Square; The Wolf, the Duck, and the Mouse,an E. B. White Read-Aloud Award winner;Triangle; Sam and Dave Dig a Hole,an E. B. White Read-Aloud Award winner and a Caldecott Honor Book; andExtra Yarn,which received a Caldecott Honor and aBoston Globe-Horn BookAward. Mac Barnett lives in California.