Lili is so quiet that her teacher marks her absent during roll call. She never gets a partner when the class pairs up because no one knows she’s there. Lili likes to spend recess curled up in a corner of her classroom with the guinea pig, Lois. Lili’s classmate Cassidy isn’t quiet at all. In fact, she’s a steamroller, and she’s chosen Lili to be her friend. Cassidy takes credit for Lili’s work and eats the cake from Lili’s lunch, and Lili doesn’t say a word in her own defense. But when Cassidy takes Lois out of her cage without permission (“Let’s give Lois a haircut . . . Let’s pour glue in her water”) Lili finds her voice at last (“STOP IT!”). Gennifer Choldenko deftly uses humor to illuminate characters and situations that will be immediately recognizable in one way or another to many children in an entertaining picture book invitingly illustrated by S. D. Schindler. (Ages 5–8)