Endpapers: FRONT: Gray scattered with small rocks, BACK: Bright freen scattererd with grass, flowers, and tiny mushrooms growing
Liam lives in a city of concrete, with nothing growing. One day he cllimbs up to some abandoned overhead railroad tracks and discoveres some weeds and a tiny tree trying to grow. So he becomes a gardener, watering and pruning and caring for the weeds. The weeds and mosses, because of this care, begin to spread. Eventually it travels the lenght and breadth of the abandoned tracks, down the sides of the bridge, and onto roofs of nearby building. All it took was the gentle caring of one boy.
In the Author's Note in the back of the book, Brown describes an old elevated railway on the west side of Manhattan that was abandoned in the 80's , then "redecorated" by nataure. I'd sure love to discover it. I wonder if it still exists?