This wordless book tells of a girl getting on on a subway train with her parents.  While all the other adults are occupied (reading, sleeping, etc.) the girl watches out the window, noticing when they come out of  a tunnel into a sunlit hillside with lots of little people flagging down the train.  She follows, serving to rescue one of the little people and his plane which had been caught in a tree.  They follow her home and offer in thanks a small plant which grows into a large tree in her urban neighborhood.  The book’s bright, graphic illustrations invite the reader into studying the plot they portray.  It can be a useful tool for oral language development with young readers and a writing prompt for older students.