Devil's Back is a special episode that was only released on the Mountain Engines DVD.
No 6 doesn't take his duties of taking The Truck. But he rescues climbers and is given an new name, Patrick.
- Lord Harry
- Ernest (TV Series) (cameo)
- Shane Dooniey (not yet introduced)
- Alaric (cameo)
- Eric (cameo)
- The Truck
- First apperence of The Truck.