Granpuff is the first episode ever made in Season 4.
It is a cold wintery night on the Island of Sodor and the hollowing wind keeps the engines in the shed awake. Toby decides that what the engines need is to listen to a story. Duck chimes in the story must have a happy ending. Thomas tells the others a story his driver had told him recently about Duke:
Once upon a time, there were three engines who lived on their own railway. Their names were Duke, Stuart, and Falcon. Duke was the oldest of the three and had been named after the Duke of Sodor. Duke felt very proud of this and decided it was his responsibility to keep the younger engines in line. While other engines came and went, Duke outlased all of them. Stuart and Falcon gave Duke the nickname "Granpuff" and were very fond of him, but did sometimes tire of his bossiness and would occasionally tease him.
Duke warns Stuart and Falcon that if they do not behave, they could end up like Smudger. Stuart and Falcon are curious about Smudger, so Duke tells them about him. Smudger was a show-off, who ran roughly and often derailed, spilling his loads. Duke tried to warn Smudger, but Smudger simply did not care and laughed at Duke. But he quickly stopped laughing when the manager told Smudger he was going to be useful one way or another. Smudger didn't laugh at that and from then on, the only running Smudger did was running as a generator behind the (Prison/Jail) shed. He never went on the rails again.
Stuart and Falcon began behaving better and all three remained friends for years. However, this all ended when hard times came. The mines that the engines depended on for work closed and the railway soon followed. As a result, the engines were all put up for sale. Stuart and Falcon were bought together, but no one wanted to buy an old engine like Duke. Stuart and Falcon promise Granpuff they will find another railway for him to run on.
Duke's crew oiled and greased him one last time, they put him to sleep snuggly in his shed and bid him a final goodbye as they had to leave to find new jobs. Duke then went to sleep, waiting for the day he would be able to run again. Years went by and torrents of rain washed soil down from the mountains and countryside grew over the shed. No one would know from looking that a small shed was there, let alone an engine asleep inside.
Percy is upset and tells Thomas that is not a happy ending. Thomas tells Percy that there is, but the ending will have to wait for another night.
- When Stuart and Falcon pass Duke with their trucks, the lighting changes, indicating that the film was cut.