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.

Gordon has problems with his fire and the others joke of gremlins. Although the turntable in the goods yard malfunctions, Gordon manages to get to Kirk Ronan before Thomas to pick up a special visitor. At Wellsworth, the passenger's dog runs away and, after confronting a bull, runs away again into Thomas' cab.