When a major delivery needs to be made to the Mainland that could potentially put Sodor on the map, Thomas has to prove himself that he is worthy of not only taking the delivery, but also being on Sir Topham Hatt's railway, with the help of his best friends Percy & Rosie. Meanwhile, Diesel is planning to steal Thomas' thunder and eradicate steam locomotives once and for all, and Edward, Henry and Toby band together to try and put a stop to his scheme.
