|For other uses, see Pop Goes the Diesel (disambiguation).|
- “Hurray! This will be the best birthday party ever!”
One busy day, the Fat Controller sends Thomas to assist Diesel at the quarry. Diesel is not happy to see Thomas and tells him that the Fat Controller is thinking of scrapping steam engines. This leaves Thomas feeling sad and worried.
Next day, fresh fuel arrives for the diesels. Diesel gloats about Thomas only have smelly coal which leaves the little tank engines feeling left out. Suddenly, Diesel's engine starts to fail—there is water in the fresh fuel.
Thomas steams off to the fuel depot to get new fuel for the diesels. He asks for all the fuel the depot has and is soon coupled to trucks loaded with fuel drums. The trucks are very heavy and Thomas has to puff hard to move them.
Meanwhile, back at the quarry, Diesel has turned as green as a leaf. It is not long before Thomas arrives at the quarry with the new fuel. Diesel is pleased to see Thomas and the new fuel. Shortly, all the bad fuel is drained from Diesel's engine and the good fuel is poured in.
Soon, the quarry is filled with the sound of work. Diesel has to admit that Thomas has saved the day and that he is a really useful engine, even if he is a steamie.
- The text implies that the fuel is poured directly into Diesel's engine.