Thomas & Friends: Season 20, Episode 12

20 - 12: Cautious Connor

Connor boasts of being a fast engine, but one day, he breaks down on the Island of Sodor and goes to the Steamworks to be repaired. Connor starts to get worried it will happen again if he goes too fast and after that, Connor starts to become the slowest engine on the island. They even start to worry that Connor would never go fast again.