By R. J. Palacio
The one your child has probably heard of: a boy with a facial difference starts fifth grade at a real school for the first time, and it's the making of everyone around him.
Auggie Pullman was born with a facial difference and has had twenty-seven surgeries. He's been homeschooled his whole life, and now, in fifth grade, he's starting at an actual school, where children stare and whisper and some are outright cruel. The story is told in turns by Auggie and the children around him, so you watch the same year through the eyes of the boy living it and the ordinary children learning, slowly, how to be decent.
This is the trail's anchor, the book everyone means when they talk about kindness, and it earns the reputation. What makes it land is that Palacio doesn't only sit inside Auggie; she hands the microphone to the sister who loves him and resents the space he takes, the friend who fails him, the classmates who grow up a little. Your child sees that being kind is a thing you learn and sometimes get wrong, not a switch you're born with. It's the emotional heart of the whole shelf.