«Stepping on the Cracks» by Mary Downing Hahn

Margaret and her best friend Elizabeth both have brothers fighting the war against Hitler and, like everyone else they know, they are filled with feelings of patriotism. But the girls are also involved in their own personal war at home. Gordy Smith, the worst bully in the sixth grade, teases and torments them, and Margaret is scared to death of him. But when Gordy and his pals Toad and Doug grow bolder than ever, Margaret and Elizabeth come up with a daring plan to get even. That's when the girls discover a shocking secret about Gordy that turns their lives upside down and draws them into a startling confrontation with family, friends, and their own strongly held ideas.