One day, the Fat Controller sends Bill and Ben to help BoCo shunt trucks in the Big Yard. They are very excited, and they work hard all morning. As a reward, BoCo says they can go for a spin on the turntable. Bill goes first, and he spins around very fast. Despite Ben protesting that it is now his turn, Bill stays on the turntable until he feels quite dizzy. Eventually, he puffs off the turntable, but finds himself on the wrong line, preventing Ben from getting onto the turntable. They both tell each other to back up, but neither twin will move.
Eventually, the Fat Controller orders both engines to back up. All afternoon, BoCo is forced to listen to the twins squabbling, and when he points out that they are both to blame, Bill steams off rudely. Then, BoCo has an idea. He tells Ben that he has to take some tankers to the factory, and so someone else needs to take the trucks full of rocks to the harbour. He asks Ben if he and Bill would be able to do it, but Ben refuses to work with Bill and tries to pull the trucks alone. However, they are too heavy for Ben to pull.
Just then, Bill arrives. Ben asks him for help, and Bill agrees. The twins apologise to each other, and set off with the trucks together. BoCo later tells Edward about his plan, and both engines are pleased that the twins have learned that Really Useful Engines always pull together.