- “James, you must be a busy bee!
You mean I have to be painted yellow and black?!”
- ―Percy and James
The Green Controller is the fifth episode of the tenth season.
Percy is alone at Tidmouth Sheds when the Fat Controller's car pulls up. Percy is very surprised to find Lady Hatt instead of the Fat Controller. Lady Hatt explains the Fat Controller has lost his voice, so he is off sick today. Lady Hatt tells Percy to give some of the engines their instructions; Gordon is to pull trucks of china plates and cutlery to Brendam Docks and must go slowly and carefully, James is to shunt coal trucks at the coaling plant and must be as busy as a bee, and Toby must collect holidaymakers from Maithwaite, take them to the Scottish Castle and be as fast as Gordon's express. Once Lady Hatt leaves, Thomas arrives and Percy tells him that he is controller for the day. Thomas asks if Percy needs any help, but Percy neglects his assistance.
Percy finds Gordon at Knapford and tells him to pull slow goods. Gordon is not very happy about this. He finds James at the washdown and tells him to be a busy bee. James gasps and asks if he has to be repainted yellow and black. Percy says yes and sternly puffs away. Finally, he finds Toby at Arlesdale End and tells him to pull Gordon's express. Toby is very surprised as Percy puffs away.
Percy then goes to check up on the other engines. At a bridge, Percy says hello to some children, but the children are laughing at Gordon being slow and James the stripy-bee engine. Toby arrives with the express, and then they notice the children and Percy. Gordon tells Percy that he is meant to be fast, not slow, James tells Percy he's meant to be red, not yellow and black, and Toby explains that he, being a tram engine, is not suitable to take the express. Percy realises that he is in a muddle and when Thomas arrives, Percy asks for his help. Thomas suggests to go back in his tracks; he might find something that may help him remember. Percy thinks this is a good idea.
Thomas and Percy go to Knapford to find see Gordon's cargo of china. Percy remembers that Gordon is to take trucks of china to the Docks. At the coaling plant they see trucks waiting for James to shunt them. Percy remembers that James is to be as busy as a bee shunting trucks. Finally, at Maithwaite, they see holidaymakers waiting for Toby. Percy remembers that Toby is to best as fast as Gordon's express while taking holidaymakers to the Scottish castle. Thomas congratulates Percy for remembering all three jobs.
At last, Gordon, James, and Toby are doing the right jobs and that evening, the Fat Controller congratulates Percy for being really useful. Percy is just happy that the Fat Controller has found his voice and hopes that he will never lose it again as being controller for the day was harder than he thought.
- Sir Topham Hatt
- Lady Hatt
- Edward (cameo)
- Emily (cameo)
- Henrietta (cameo)
- Refreshment Lady (cameo)
- Tom Tipper (cameo)
- The Storyteller (cameo)
- Cyril (cameo)
- Henry (deleted scene cameo)
- Tidmouth Sheds
- Arlesdale End
- Toby's Shed
- The Coaling Plant
- Castle Loch
- The Washdown
- Brendam (mentioned)
- One of the trucks is wearing Bulstrode's surprised face.
- The piece of paper Lady Hatt reads from appears to be a crew member's notes. The words "Thomas and Friends" and "Crew" can be seen on it.
- An image from a deleted scene shows James in his "buzzy bee" livery and Gordon derailed. It was revealed that it happened because James did not wait for a signal and ran into Gordon, and Toby crashed into James and Gordon causing a huge mess. But possibly due to time constraints, this scene was omitted.
- This is the first episode of several things:
- Tom Tipper's first appearance since the fourth season episode, Mind that Bike.
- The first time in the series where Gordon says "Oh, the Indignity!" which would later become his catchphrase in the CGI Series along with "Express coming through!"
- The first appearance of Arlesdale End since the first season episode, Toby and the Stout Gentleman which was also its debut appearance, the shed had only previously appeared in earlier seasons.
- Gordon: I am supposed to be the fastest engine on sodor, not the slowest!
- James: I'm supposed to be the reddest engine! Now no one know's who I am!
- Toby: I'm only a steam tram! The express is too heavy for me to pull!
Gordon, James and Toby explain to Percy for doing a wrong job.
- Motor Road and Rail (discontinued)
- TrackMaster (discontinued; reintroduced 2015)
- Wooden Railway (discontinued)
- Wind-up Trains
- Books - Thomas and the Green Controller, Thomas and the Green Controller, Percy's Most Important Mission (Germany only) and Bad! I Can Not Remember (China only)