Misty Valley lies along a branch line, which is often very misty. This is why Cyril (a friendly fog signalman who lives in Misty Valley) earns his keep by putting detonators on the rails to warn the engines of fog and landslides. Thomas enjoys seeing Cyril, and puffing over the blasting caps due to that they make his axles tingle. That evening, the Fat Controller visits the engines at Tidmouth Sheds to tell them that he has acquired an electric foghorn. Once he tries to test it, the ground shake