Puffing Billy is a little steam engine who carries farmers and their goods through the hills. Children like him too, because he is the happiest engine in the land. But one day disaster strikes a landslide rolls down onto the track and a lot of important looking gentlemen decide that Puffing Billy can run no longer. He is taken to a workshop and left alone in a dusty corner. For a while it looks as if he has been forgotten. But then the children who used to ride the Puffing Billy feel lonely without him and they think of a plan to put him on the rails again.