Is the sound Charlie hears from the bridge an echo, or is someone else out there? A lyrical, resonant story by poet Ted Kooser, splendidly illustrated by Barry Root. When Charlie visits his hardworking grandparents in the summer, he often is left to himself, and he is lonely. So he goes out to play by the stream, with a tin can for tadpoles, a special weed-whacking stick, and stones to drop from the iron bridge. One day he notices that when he strikes...