Plot

Though Duck silences them, Diesel blames him for the freight-trucks' taunts. Henry protests that nobody confides in the trucks, so Diesel tells them jokes about the biggest three, saying they're Duck's, since the trucks want revenge.

Diesel, the newest engine on the Island of Sodor, is having a hard time having been made to look silly in front of the trucks, who delight in teasing him. Duck sees what Diesel has gone through and stops the trucks from their joking. Duck apologizes for the trucks' behaviour, but Diesel is still furious and blames Duck for making the trucks laugh at him. The big engines are nearby and, knowing that Duck would never do that, tell Diesel so. Henry reminds Diesel that while he, James and Gordon have their differences with Duck, they would never tell the trucks about them.

By now, Diesel's hatred of Duck has grown to such a point that he wants him to be sent away and, inspired by the engines' words about trucks, makes a plan, for he will tell lies about Duck. Going into the yard the next day, Diesel tells the trucks that he laughed at the joke about him the day before and tells them some about the bigger engines and claims that he heard them from Duck. Before leaving he tells them not to tell the bigger engines he told them. The trucks find these jokes hilarious and laugh at the bigger engines and tell them that they came from Duck in order to get revenge on him for forcing them to behave.

Gordon, James and Henry, believing that Duck was the one who told the humiliating stories about them, hold a meeting and agree that Duck needs to be paid out. They decide that since Duck prevented them from entering the sheds that they'll do the same to him. Later Duck returns to the shed after an extremely hard day's work. However, when he tries to get back inside for a rest, the bigger engines instead let off a lot of steam at him. They tell him that, after telling tales about them to the trucks, they no longer trust him and want Diesel to replace him. Duck denies this and an argument ensues, but it's not long as the Fat Controller arrives to intervene and see what the commotion is. He's told of the bigger engines' accusation against Duck and, while trying not to laugh, gives Duck a chance to explain himself. Duck tells the Fat Controller that he didn't and that no steam engine would be as mean as that. Diesel comes forward and when the Fat Controller asks him what he knows, Diesel feigns shock at Duck's "actions", but claims ignorance otherwise.

The Fat Controller apologizes to Duck, saying that until he gets to the bottom of the incident that the Great Western Engine must go and work with Edward at Wellsworth for a while and kindly reassures Duck that Edward will be happy to see him. Believing that the Fat Controller has turned against him too, Duck, beginning to cry, obliges and puffs away, while Diesel smirks with triumph.