Doctor Who has already had its Pilot in An Unearthly Child, yet this episode claims to be the beginning. In some ways, it's right. This is our introduction to Bill Potts. The start of her story, just after Clara's ended. In other ways, it's like claiming 2016's The Jungle Book is the original Disney Jungle Book. It isn't. Regardless, that's the title Steven Moffat chose - and its probably this pedantic analysis of the title that he wanted fans to give. There is a literal pilot in the episode - a puddle that possesses the body of Bill's (Pearl Mackie) crush Heather (Stephanie Hyam) - but the character is not really the major focus of the episode despite being the primary antagonist, so I doubt Moffat is referring to her. More on the puddle pilot later.

The Pilot is interesting in that much like The Return of Doctor Mysterio it creates a large gap between the last episode and this one. Moffat's Doctor Who has done this often to accommodate Big Finish but this time it's different. We are told The Doctor (Peter Capaldi) and Nardole (Matt Lucas) have been guarding a Gallifreyan vault for somewhere between 50-70 years, and during this time the Doctor has been posing as a university lecturer at St Luke's University in Bristol. We find out in the following episode Smile that he swore an oath not to leave Earth. This is perhaps the most compelling mystery of the Moffat era, and arguably the most unpredictable story arc the 2005 revival has done.

During his time lecturing at St Luke's University The Doctor notices that a canteen worker has been regularly sneaking into his lectures, and has been reacting differently to his lectures compared to the students. The students look puzzled when they don't understand something. The canteen worker smiles. Her name is Bill Potts, and The Doctor decides to make her a student - with himself as her private tutor. Meanwhile, Bill's crush Heather notices something strange about a puddle. Instead of reflecting, it shows the same symmetrical face back. The puddle chooses Heather as its pilot and pursues The Doctor, Bill and Nardole across time and space hoping to take Bill with her on its space journey.

The puddle monster is a fun threat, but much like 2005's Rose the episode is more about introducing Bill than it is the monster-of-the-week. This can lead to the puddle monster feeling a little under-developed compared to other Moffat creations such as The Silence and the Weeping Angels. It's a cool concept that does what the best Moffat monsters do - take an ordinary childhood fear like stepping into a puddle and turn it into an alien menace - but because it isn't the episode's primary focus, it never feels like a credible adversary for The Doctor. It's for this reason that I hope the puddle monster appears again - I'd like to learn more about its origins and if it has any connections to The Flood from The Water of Mars (it bears striking similarities). Hopefully next time the puddle monster won't be played by Stephanie Hyam though.

Stephanie Hyam is terrible. She is possibly the most wooden, dull, uncharismatic actor ever to appear in Doctor Who. Every line she speaks is said in an emotionless monotone voice that makes it sound like she's under a Cyber-conversion process - in fact, maybe she was about to become a Mondasian Cyberman before the puddle monster took over? They are returning in the two part finale. I have no idea what Bill sees in Heather because Stephanie Hyam's portrayal ironically makes her come across as wet and boring. Couldn't the puddle monster have chosen someone more interesting as its pilot?

Thankfully, Bill Potts is a very interesting character. Bill is a wonderfully inquisitive companion brilliantly played by Pearl Mackie. She's the companion who asks questions that have never been asked before, such as why the words on the police box exterior are in English and 'Where's the toilet located in the TARDIS?'. The latter is something I've personally always wanted to know. Why has no companion asked that before?

As for The Doctor's other companion Nardole...well, he's just kind of there at the moment. Matt Lucas isn't given anything of note to do, and it's hard to form an opinion either way. I'm not sure what the point was in bringing back Nardole: he was barely in The Husbands of River Song, made little to no impact in The Return of Doctor Mysterio and in both Smile and Thin Ice he features even less. He may as well not even be there. Matt Lucas isn't really needed when Pearl Mackie does such a good job as Bill.

The Pilot contains some of Steven Moffat's best writing for the show. The opening scene between the Doctor and Bill is probably one of the best exchanges between Doctor and companion (even if it feels like it should have come later into the episode) and definitely one of the Moffat era's finest scenes. Much like Rose there is generally a slower pace to this episode, but it's a wise decision that helps us get to know who Bill is as a character. After the frantic pace of Series 9, it's a very welcome change of pace too. Having episodes where a lot of things happen is very fun to watch, but it runs the risk of becoming exhausting for the viewer if done too often.

The Pilot's main focus may be to introduce new viewers to the show, but there are plenty of nice references and call backs for those of us who are already fans. For instance, the Movellans from 1979's Destiny of the Daleks appear briefly fighting a war with The Daleks, and Nardole is given the Fourth Doctor's Sonic Screwdriver. There are even framed pictures on The Doctor's desk of his granddaughter Susan Foreman and wife River Song.

Intriguingly the camera lingers for a very long time on Susan's photo. Could it be foreshadowing her return? The Doctor did say that one day he would return to her... (NB: Susan didn't return.)

Probably the best piece of fan service in the episode is the Impossible Girl theme playing when Bill refuses to have her memory wiped by The Doctor. It's a touching moment as the Doctor remembers his own memory being wiped, and hopefully is foreshadowing the Doctor beginning to recall who Clara is. It would be a shame if this incarnation of The Doctor regenerates without remembering his most significant companion.

Overall, The Pilot is a good introduction to the character of Bill Potts. Pearl Mackie does a great job atplaying when Bill refuses to have her memory wiped by The Doctor. It's a touching moment as the Doctor remembers his own memory being wiped, and hopefully is foreshadowing the Doctor beginning to recall who Clara is. It would be a shame if this incarnation of The Doctor regenerates without remembering his most significant companion.

Overall, The Pilot is a good introduction to the character of Bill Potts. Pearl Mackie does a great job at playing the part of Bill, especially in the knowledge that it's her first proper TV acting role. The puddle monster is a cool if underdeveloped concept and there are some nice callbacks to earlier episodes. However Matt Lucas as Nardole seems like an unnecessary inclusion and Stephanie Hyam is dreadful as Bill's crush Heather. The Pilot is essentially the 'Rose' of the Moffat era, and does just as good a job at introducing us to the new companion. If Bill is going to be the new 'pilot' leading new viewers into the world of Doctor Who, then I think the show is in safe hands.