Doctor Who: Every Modern Companion's DEFINITIVE Episode
4. The Pilot (Bill Potts)
Introductory episodes, by nature, can easily qualify as definitive, so they're a bit of a cheat for this list – hence why we've avoided them!
In the case of Bill though, The Pilot is such a clear statement on what Moffat was trying to achieve with her (and by extension, Series 10) that it simply has to be the pick.
Series 10 was billed as a new start, a breath of fresh air after the cerebral and serious tones of Capaldi's first two series. Part of this shake-up was a return to 'normality' for the show, less tied into big mythos and more centred on ordinary people. Enter... Bill.
The Pilot serves as a perfect introduction because it doesn't overcomplicate Bill, and it doesn't overcomplicate the plot. That's not to say Bill is lacking depth (far from it), but rather that the show is very upfront about who Bill is – she does what it says on the tin. There's no crazy lore or mystery behind Bill, she's simply an inquisitive, chatty, funny woman with a thirst for the unknown. What you see is very deliberately what you get, and Moffat was right: at this stage of the revival it very much was a breath of fresh air.
The Pilot makes a conscious effort to contrast Bill with the 'most important woman in the universe' companions that have come before her. The Doctor notices her not because she is extraordinary, but because she's unapologetically curious. She doesn't do anything particularly special or brave to win her spot in the TARDIS, she just asks good questions and makes good company.
The teacher/student dynamic is absolutely key to this series, and this episode serves as a perfect introduction to it. It's a bit Seven and Ace, but this time, the Doctor is quite literally her university tutor. Bill functions as a genuine audience surrogate in a way that we hadn't had since Donna.
She asks questions the show needs asked, but not in a naive way, and also has a subversive way of thinking that leads her to ask questions that haven't occurred to other companions in the 60 years of the show, often with a sarcastic and slightly meta sense of humour. Pearl Mackie is supremely good at disguising exposition dumps and making them seem more natural.
What the episode also does particularly well is establish that Bill’s emotional and narrative arcs aren't about uncovering hidden secrets, but about expanding on the traits she already has.
Her relationship with Heather and her mourning of her mother are very simple, everyday troubles (yes, Heather turns into a sentient puddle, but you know what we mean), and throughout the series the things we see Bill dealing with outside the monster of the week are refreshingly relatable: bickering with her foster mum, trying to get on the property ladder and juggling homework.
In all instances, Bill faces everything with a smile. And we see that right from the beginning of her journey.