On the Island of Sodor, two kinds of engines help keep Sir Topham Hatt's railway running smoothly - steamies and Diesels. But is the island big enough for both? It's not always easy for these engines to put aside their differences and work together. See what happens when the diesels tease Thomas. Will Thomas come to their aid when they need this Really Useful steamie's help? And when Gordon develops some very loud squeaks and rattles, will Sir Topham Hatt retire him to the yard for good? That's what the diesels say! Get on board with the steamies and the diesels and see how they finally learn that, from brake pipe to buffer, all engines are more alike than not.