It's winter, and lots of snow has fallen on Sodor and all the roads are blocked. Bertie can not take any passengers so Percy is told to pull a passenger train for the day. Percy is pleased, but worried as he has not pulled a passenger train for quite some time. The Fat Controller instructs Gordon to show Percy what to do.
At the depot, Percy reverses towards his carriages, but he bumps them too hard. Gordon impatiently shows Percy how it should be done. Gordon is very proud when the yard manager praises him for his smooth puffing. Gordon becomes big-headed and starts to show off. Gordon steams past a station and is determined to show off to the passengers on the platform. He is so busy showing off, that he does not notice the icy rails and slips into a big bank of snow. The Fat Controller is very cross.
That evening, Gordon watches Percy puff slowly into Tidmouth Sheds. This time, Gordon praises Percy and tells him that he has learnt well. He hastily adds that it was because the little green engine had a very good teacher.