Thomas is shocked to learn from Percy that there is an engine with a branch line as famous as his and that the engine might visit. The engine, Stepney, has become bored with the Bluebell Railway and is delighted to discover that he has been invited to visit the North Western Railway. When Thomas hears the news, he is jealous and refuses to meet Stepney, but the others welcome him and he works with Duck happily all day. When it is time for Thomas' last train, he is furious to be shunted to let another train pass and is shocked to find Stepney pulling it. Thomas grumbles about it next morning, but Stepney explains the situation: he took a passenger who ordered a special train which Duck let him take, yet when he is unable to finish, Thomas realises he was nervous since he did not know the line. Stepney flatters Thomas by calling him an expert, and Thomas, no longer jealous, proceeds to tell Stepney all about his branch line.
This episode and Rusty to the Rescue are the only episodes of Season 4 to not be released on VHS before airing on TV, but the UK Narrations were released before airing on TV.
In the UK and international versions, when the special is ordered, music is heard. This is absent in the US version. Towards the end of the episode, the background shunting noise is cut off and some whistle sounds are also missing in the US version.
On PBS Sprout airings, this episode uses the unrestored opening credits.
The area that Thomas puffs down in the very first scene is the same set Sir Handel and George had their altercation, but with standard gauge track added.
When Thomas puffs past the field at the beginning, studio equipment is visible in the top-right corner.
While Percy is telling Thomas about Stepney, as the camera is on Thomas, Percy's right lamp iron is bent but when the camera is on Percy, it is normal.
While the engines wait for Stepney, a tar wagon, perched on another tar wagon, is visible behind Gordon and Henry.
Stepney has Smudger's whistle sound in the US version and Rheneas' in the UK and international versions. Rheneas' whistle is used once in the US version as well.
Stepney has Duke's whistle sound when he is working with Duck.
In the US version, when Percy finishes talking about Stepney, his whistle sound is a higher pitched version of Thomas' whistle.
In the UK and international versions, Gordon, Duck and Douglas have the same whistle sound.
When Thomas says "Why are we waiting? My passengers are being delayed," a black box is attached to his cab.
In the US dub, George Carlin mistakenly says "Stop all train!" instead of "Stop all trains!"
Stepney is already wearing his express head lamps long before he is allocated to take the special train.