Three very Horrid Lorries arrive on Sodor and start taking over the engines' jobs. Percy and Toby receive the worse at the end of the tether. But eventually, the tables are turned, as the lorries get their comeuppance in due course. The engines work even harder to ensure the lorries never return.

On his way to his wife's birthday, the Fat Controller's car becomes stuck in a pothole. He hitches a lift in Caroline, who breaks down, and then George, who loses control and crashes into a muddy pond. Thomas, luckily, is nearby and the Fat Controller is forced to act as his "relief" fireman to reach the party in time.