- “Hey Guys! Presenting the new Rebecca!”
- ― Kevin
What Rebecca Does is the fifth episode of the twenty-second series.
Rebecca is so impressed by Belle putting out a fire with her water cannons, Marion's steam shovel and Harvey's crane that her enthusiasm makes her friends feel very good about themselves. This leads Rebecca wondering if she has any special qualities too.
- Bill and Ben
- Annie and Clarabel
- The Teacher (cameo)
- One of Dowager Hatt's Friends (cameo)
- The Bird Watcher (cameo)
- Albert's Wife (cameo)
- Diesel 10 (claw only)
- Knapford Station Yard
- Tidmouth Sheds
- Sodor Steamworks
- Brendam Docks (stock footage)
- Sodor Shipping Company (stock footage)
- Joseph May as Thomas
- Rob Rackstraw as James
- Christopher Ragland as Percy
- Jules de Jongh as Emily
- Rachael Miller as Rebecca
- Teresa Gallagher as Belle, Annie and Clarabel
- Steven Kynman as Duck
- Keith Wickham as Harvey
- Olivia Colman as Marion
- Tracy-Ann Oberman as Daisy
- David Bedella as Victor
- Rasmus Hardiker as Bill
- Matt Wilkinson as Ben
- Kerry Shale as Kevin
- At the end of the episode, Thomas mentions the events of the seventeenth series episode, Gone Fishing. Stock footage from the said episode is used.
- This is the first episode where Rasmus Hardiker voices Bill and Matt Wilkinson voices Ben after Jonathan Broadbent left the cast.
- This episode marks Bill and Ben's first speaking roles in an episode since the nineteenth series episode, No Help at All.
- This episode marks Marion's only speaking role and Harvey and Belle's only appearances in the twenty-second series (not counting stock footage appearances).
- When Number One Engine aired on Nickelodeon, What Rebecca Does was paired with the episode instead of Thomas in the Wild. The original airing was fixed putting the right episode in and What Rebecca Does was paired with Forever and Ever on 7th December 2018. Some time later it was repaired with Thomas in the Wild in present airings.
- A voice clip from the twenty-first series episode, Stuck in Gear was reused when Harvey threw his load (second time since that episode).
- Diesel 10's claw is used in Rebecca's fantasy, despite him not appearing in the episode.
- This episode aired before Confusion Without Delay, meaning the US audience would not know who Rebecca is.
- When this episode aired on Nickelodeon in the US, the music and sound effects were echoed.
- Apart from Thomas reading the title aloud and talking directly to the audience before and after the story, this episode does not include any narration.