The World's Strongest Engine / Scaredy Engines

S6, E6: Diesel is brought in to help after Henry breaks down. As Diesel shows off, the trucks decide to cause trouble...and Diesel quickly learns that he is not the world's strongest engine. On Halloween, Percy is running scared from Edward's ghost stories. Knowing this, Thomas teases him. But when Thomas is left alone to finish the job at night, it's Thomas who's the scaredy engine.