When Harold breaks down, Thomas and Duck are asked to take him for repairs but Thomas has something more fun in mind which only leads to trouble. Luke and Millie switch jobs for a day and quickly learn how much they truly like their own work. Percy is having a bad day and feeling very unlucky but when a friend gives him a lucky charm, he thinks things might turn around. Caitlin is so excited to spend the night on Sodor that she doesn't let the other engines get any rest so they find jobs to keep her busy through the night without realizing that she doesn't know much about how things are done on the island. When playful Paxton convinces Thomas to be silly and drive over some bumpy tracks, he doesn't realize that his actions will make Thomas 'lose his puff' and he scrambles across the island in an attempt to help his friend.