Air date: September 23rd, 2002 (UK)
Misty Valley lies along a branch line, which is often very foggy. This is why Cyril, a friendly fogman who lives in Misty Valley, earns his keep by putting detonators on the rails to warn the engines of fog and landslides. Thomas enjoys seeing Cyril, as well as the tingling sensation in his axles when he puffs over the blasting caps. That evening, the Fat Controller visits the engines at Tidmouth Sheds to tell them that he has acquired an electric foghorn. He also says that Cyril will not be needed anymore and will be given a much-needed rest. Thomas is very disappointed to hear this. The foghorn is put on the hillside in Misty Valley.
While Percy is puffing through Misty Valley the following day, the foghorn sounds. Ironically, after Percy is out of sight, the vibrations from the foghorn create a landslide, which sweeps onto the track and destroys it in the process. Thomas comes along, and as the horn is not working, Thomas has no idea about the landslide and derails. Then, Toby and Henrietta come along. There is no way of stopping them until Cyril comes to the rescue. He puts down a cap to warn them, just in the nick of time. Once the mess is cleared up, Cyril is reinstated as Misty Valley's fogman.
This episode contains examples of:
- An Aesop:
- When it comes to a certain job, like a fogman for example, replacing a human with a machine can be disastrous.
- Don't fix what isn't broken.
- Big Damn Heroes: Cyril arrives just in time with his detonator to warn Toby about the landslide while Thomas is derailed.
- Cool Old Guy: Cyril the Fogman, who has proven to be more reliable than the foghorn and shows no resentment over his replacement.
- Hoist by His Own Petard: A device meant to improve rail safety winds up creating a hazard instead.
- Russian Reversal: In the end, the Fat Controller declares that rather than replace Cyril with the foghorn, they'll replace the foghorn with Cyril.
- Track Trouble: The foghorn causes a landslide to block the line. Thomas doesn't see it in time and crashes into it, coming off the rails.
