Size matters, but Tree needs convincing. At six feet, three and a half inches, he's the tallest seventh grader in the history of his school, and people expect big things. But he's not good at basketball, he looks much older than he feels, and his parents' divorce is all too new. He copes by helping people like his grandpa, a Vietnam vet who's just had part of a leg amputated, and Sophie, a new girl who's being taunted at school.

Taking things apart helps, too. He learned that from Grandpa. And in the process of seeing how lamps get rewired and laser pens work, in Grandpa's powerful memories of the Vietnam War, in helping an old soldier learn to walk again, in Sophie's insistence that Tree be himself, he begins to heal from the divorce and learns to stand tall. But when a flood threatens his home, Tree's new-found confidence is put to the test.

Newbery Honor-winning author Joan Bauer's story, packed with memorable characters and her trademark humor, is about finding purpose in tough times. And it's about Tree's giant heart, not his giant size, making him a hero.