Harold's rotors jam up, so Duck has to take him to the rescue centre in order to be repaired, with Thomas as his back engine, to make sure Harold can fit through any low or narrow gaps. Thomas wants to show Harold Sodor's sights from the ground, but Duck wants to go directly and promptly to their destination. The two mindsets collide when each engine wants to perform the task their own way

After Percy suffers a bout of bad luck, he starts to wonder if he is simply an unlucky engine. When he tells Stephen, Stephen decides to give Percy his old lucky horsehoe. Things seem to turn for the better for Percy, but when he realises he's lost it, he feels he cannot rescue Bill and Ben.