|Season One STMY, Episode Ten|
|Air date||Saturday 22nd of November, 2014|
|Duty of Care||Aftermath|
Iris the new Class 14 diesel has arrived to take charge of The Container Yard. But Bill and Ben are up to no good and want to have some fun with the new diesel. After pranking her, she decides to give them a taste of their own medicine. With the help of Diesel and Henry, Iris gets her own back on the twins.
- Bill and Ben
- Emily Helen Hatt
- Gordon (does not speak)
- Percy (does not speak)
- Sheffield (does not speak)
- BoCo (does not speak)
- Edward (cameo)
- Patrick (mentioned)
- Part of this episodes script was released on November 6th by WildNorWester for people to audition for different roles.
- References to Wrong Road, Bad Apple and The Diseasel are made.
- A colored picture of Iris is used for the background credits at the end of the episode.
- TobyandMavisforever makes her first appearance in the voice cast.
- Two of Iris' lines sound slightly different in recording to the rest. This is because WildNorWester made some mistakes in the script and therefore, TobyandMavisforever copied them when recording. She had to redo the lines.
- WildNorWester as The Narrator and Diesel
- Lady TehPikachu as Bill and Ben
- David Moyle as Peter
- TheScotsmanReturns as Henry
- TobyandMavisforever as Iris
- Jinty1798 as Bear
- ANB as Emily Helen Hatt