Every day a girl stands at her window and waves to the engineer of the train that passes on the nearby tracks - and he waves back! The little girl is curious about the engineer, about where he came from and where he goes, which makes her wonder if she might go away, too, some day. This beautiful free verse picture book explores the magic of a connection made between strangers, while also pondering the idea of growing up, and what might lie beyond a child's own small piece of the world.