Air date: September 21st, 1998 (UK), September 16th, 1999 (US)
Gordon is having problems with his fire, and the firelighter suggests it is due to gremlins. Thomas and Percy get excited, but James thinks it is nonsense. The engines argue about the issue until the Fat Controller arrives and informs the engines that he's got a VIP coming and she has heard a lot about how Really Useful the engines are. After Percy states about the gremlins in Gordon's fire, the Fat Controller warns Gordon to be on his best behaviour as he's taking the VIP.
The goods yard's turntable malfunctions with the special coach on it, making Gordon late. He makes up for the lost time and manages to get to Kirk Ronan on time. Thomas arrives with the special passenger and Gordon takes her to Wellsworth. On the way, Gordon goes at high speed, much to the passenger's disliking. At Wellsworth, the passenger's Dalmatian runs away after being frightened by Gordon's loud whistle and, after confronting a bull in a field, runs into Thomas' cab and rides there during the trip to the docks.
At Brendam, Thomas' fireman inquires about the dog's name, to which the Fat Controller's VIP decides to rename him "Gremlin" after the day's events. After the Fat Controller laughs at having finally met one, he reveals the woman is his mother and that she agrees with him about how Really Useful the engines are, to which he adds that his mother is always right.
Tropes featured in the episode:
- Karma Houdini: Gordon was warned by the Fat Controller not to go at high speeds, but after Thomas arrived late with the special passenger, he does it anyways, thus splashing water over the special passenger who was taking a shower. He never got scolded for it.
- Only Sane Man: James is the only engine to understand there are no gremlins, it's "just an excuse for when things go wrong."
- Saying Sound Effects Out Loud: In the UK dub, every time Gremlin barks, Michael Angelis reads it with a deadpan, "A woof woof."
- Silence, You Fool!: The Fat Controller does this to the engines who were arguing about issues of gremlins.
