Air date: September 8th, 2020 (UK); September 1st, 2020 (US)
One morning at Knapford station, a mysterious barking is heard as Grodon tries to speak, earning him some teasing from James. When Nia arrives, she soon discovers it belongs to a stray dog, who later relieves itself on the wheels of a horrified James. The dog later reappears at Dryaw, where Emily warns the Fat Controller just before he trips over it. He then decides to call a dog warden to take care of it - to which the dog runs away and over the fence.
The dog then appears in front of Thomas, who decides to take it on board and try and find its home, despite getting protests from Annie and Clarabel. He asks Bertie if he knows anyone who has lost a dog, but to no avail. To try and find the owner, Thomas' crew put up posters at stations along the line.
While stopped by a workman's hut, the dog notices a squirrel and gives chase. While trying to retrieve the dog, Thomas accidentally runs into a branch on the tracks and is derailed in the forest. The dog then takes Thomas' driver's cap and runs off with it.
Meanwhile, back at Knapford, the Fat Controller is with Albert and his son Thomas, who asks when "big Thomas" will be arriving. Just then, the dog runs up the platform, bringing with him Thomas' driver's cap. Soon, the Fat Controller realises what has happens and asks Emily to follow the dog and help find Thomas.
Emily eventually finds Thomas in the woods (assisted by the dog) and after fetching Rocky, takes him back to Knapford. At Knapford, the Fat Controller begins to scold Thomas, but is interrupted by the dog. Thomas explains that he was trying to find the dog a home, to which little Thomas asks his father if he can keep the dog. Little Thomas promises to look after the dog and bring it to see Thomas, and gives him the name "Fuzzy" to everyone's laughter.
This episode contains examples of:
- Catchphrase Interruptus: Before the Fat Controller could finish saying "confusion and delay", the dog jumps all over him.The Fat Controller: Thomas, you have caused a lot of confusion and dela— [gets jumped on by the dog]
- One-Steve Limit: Albert's son, Thomas returns in this episode as a young boy. To tell him and Thomas the Tank Engine apart, the former is referred to as "Little Thomas", and the latter is referred to as "Big Thomas".
- Soap Opera Rapid Aging Syndrome: Little Thomas was introduced as a baby in "Thomas the Babysitter". In this episode, he's aged up to be a young boy.
- Urine Trouble: The dog urinates on James' wheels.James: No, no, no! Not on my shiny wheels!
Thomas: They're certainly shiny now, James!
