|This article is about the Story Library book. You may be looking for the engine or the Engine Adventures book.|
Diesel, re-titled Diesel the Mean Engine in 2011, is the twenty-eighth book in the My Thomas Story Library series.
Percy is unwell so The Fat Controller orders another engine, but Diesel is the only one available. Thomas soon teaches him the ways of the branch line, but the trucks tease Diesel and soon put him in trouble. But Diesel proves himself a useful engine when Thomas falls into trouble.
- Sir Topham Hatt
- Daisy (does not speak)
- Annie and Clarabel (do not speak)
- Bertie (does not speak)
- Terence (cameo)
- Duck (poster cameo)
- Sir Handel (poster cameo)
- Alice and Mirabel (poster cameo)
- In one illustration, Thomas is missing his lamp iron's