Don't Go Back

Don't Go Back is the fourteenth episode of the twelfth season.

Plot
Thomas and Diesel are to load and shunt trucks of stone for Henry, but they get sidetracked when Diesel claims Diesels are faster and declares a backwards race to prove it. Unfortunately, the three heats (which ends in a draw) cause Mavis, 'Arry, and Bert to be derailed after Thomas and Diesel collide with them. And when Henry arrives, none of the trucks have been loaded. While Thomas arranges the train and collects Rocky to put Mavis, 'Arry, and Bert back on the rails, Diesel clears away the mess from the races. When the two are done, Diesel challenges Thomas to another race, which Thomas orders to be forward. This time, both arrive at the quarry gates at the same time!

Characters

 * Thomas
 * Henry
 * Diesel
 * Mavis
 * 'Arry and Bert (do not speak)
 * Rocky (does not speak)

Locations

 * Sodor Slate Quarry

Trivia

 * Stock footage from Hector the Horrid! and The Great Discovery is used.
 * In the last race, a workman can be seen holding a racing flag.
 * A third rail is used to make Mavis come off the tracks.

Goofs

 * Diesel wasn't blamed for anything when he was equally responsible for the disruption at the quarry.
 * Diesel blows steam from his cab when he and Thomas shunt the trucks of rubble and wood.
 * Thomas should have realized he pushed Mavis off the track.
 * 'Arry and Bert's CGI faces are smaller than usual in some scenes.
 * In the first race, how did Diesel get on the same line as Thomas when no points are seen going to that track?
 * A brakevan should have been added to Henry's train.