Excitement spreads across Sodor with the arrival of a new and unusual engine. Worrying they'll be replaced by the fast and modern Hugo, the engines fail to be good friends by not making him feel welcome. When they stop to listen, they realize that Hugo is a very special engine who truly belongs on the rails. Elsewhere things get spooky when the engines see a ghost train and Percy goes on a troll hunt. Skiff takes Sir Topham Hatt on a wild ride in search of a mermaid, Hugo dreams of taking to the skies and Judy and Jerome learn what it takes to feel really useful again.