Horwich wants to show his gratitude to the other engines for saving him, and there is only one way he can think of.
Horwich is enjoying his new life in Euston. The engines saved him from scrap and Horwich has a plan to thank them in his own way. His driver is stunned when Horwich tells him he wants to go to Crewe. Horwich doesn't explicitly say why, but he says its about something they've been talking about for some time. The driver would rather he just told the engines he's grateful, but Horwich insists that it's all part of his big thank-you plan to them, and now is the best time to do it. Eventually, his driver comes around to his idea. However, he reminds his engine that getting to Crewe in a day will be difficult, but promises to think of something. Once they get to Euston station to collect their coaches, they see an express train for Arthur sitting at the platform. Horwich innocently asks where it's bound. Jimmy answers that it's going to Glasgow. He further explains that Arthur will switch it off to another engine at Crewe. Horwich excitedly tells his driver of this agenda, and suggests that he can ride behind Arthur to Crewe. His driver advises against the idea, given the trouble it could cause them with the stationmaster, the shedmaster, and the railway board. He reasons that Arthur is a high-speed express engine and that traveling with him could significantly damage Horwich. His point is proven when Arthur backs onto his train and asks his passengers to get in quickly, and says they will be in Glasgow in no time. Horwich agrees it would be best to look for another way to get to Crewe.
That evening, Horwich is alone with his thoughts when John comes in complaining about being overworked. He grumbles that a 9F has broken down and now he must take his heavy goods in relays to Derby. Horwich and his driver see this as an opportunity to get to Crewe, as it is only an hour away from Derby, and they can easily find an excuse to get up there. The next morning, Horwich's crew speaks to the yard foreman and shedmaster about having Horwich help with the goods trains to Derby. The men are reluctant but his driver convinces both that Horwich is suited to the task. Eventually they both agree. The yard foreman exprlains that John leaves with the first train at 10:00 and the next leaves at 3:00. He tells them to get their jobs done on time, so they can take the 3:00 train. The shedmaster warns the old tank engine that although he doesn't know what he is up to, he hopes he knows what he is doing. Afterwards, they get to work, determined to complete all of their jobs on time. Their conversation however catches the attention of Den. Horwich and their crew completes all of their jobs on time but then the unforseen happens: at the station, Ivatt has trouble building up steam. Horwich is forced to take his afternoon passenger train. He protests that he has a goods train to take to Derby. The stationmaster doesn't believe him, and Jimmy is curious as to why he needs to go there. Unable to offer an explanation, Horwich is left with no option but to leave with Ivatt's train.
By the time he returns to the yard, all he can do is watch his train disappear behind another engine. Den explains that they had already mended the 9F and did not need him after all. Horwich wonders how his is going to get to Derby. That is when we find out about Horwich's scheme: Den reveals that he knew all along about his plans to get to Crewe, find Fred, and bring him home! He also admits that while he does not see eye-to-eye with steam engines, he has a deep respect for Fred. He holds him in high regard for his high wisdom and his unconditional kindness towards all engines, regardless of class or type. Den agrees that it would be beneficial for Fred to come back to Euston. He explains to Horwich that he took the liberty of separating some vans from the 3:00 train that were heading for Scotland. He advises Horwich that if he delivers them to Crewe, another engine can take them on their goods, and he will be free to search Crewe works for Fred. Horwich is delighted and grateful for Den's help. He jokes that he is not as bad as William and John describe him, and is quite endearing when he wants to be, much to Den's embarrassment. Before Horwich sets off, Den warns him to be careful. Crewe has changed considerably from what he has been told. Horwich thanks Den once more for his help, and asks him not to tell anybody why he has gone. Den agrees. The line is clear, and Horwich finally puffs away to Crewe to find Fred.
- This episode marks the final apperance of Den to date.