Whenever a new companion is introduced to Doctor Who, their first episode has one important question to answer, for characters and viewers alike. In "The Pilot," the Season Ten premiere, Bill Potts (Pearl Mackie) asks the Doctor this question in her very first conversation with him. 

"Why me?" 

Watching every new companion's first episode is like watching a blind job-interview: one in which the person being interviewed has no idea that they're a candidate, or even what the job entails. And it's never a terribly conscious process for the Doctor, either: he is seldom eager for—or even open to—a new companion, and I doubt very much he could describe what he's looking for in one.

But he knows it when he sees it. ("I never know why," he told Clara Oswald in "The Snowmen." "I only know who.")

We, on the other hand, can almost see the Doctor checking boxes on a clipboard as a potential new companion accidentally says or does the right thing to prove their worthiness. In "Rose," the first episode of the modern era, Rose Tyler's first conversation with the Ninth Doctor—after being attacked by living mannikins—revealed a clever mind at work: 

Rose: Who were they then, students? Is this a student thing or what?
Doctor: Why would they be students?
Rose: I don't know.
Doctor: Well, you said it. Why students?
Rose: Because, to get that many people dressed up and being silly, they've got to be students.
Doctor: That makes sense. Well done.
Rose: Thanks.
Doctor: They're not students.

Even though her conclusion was wrong, the Doctor appreciated her logic, and her desire to puzzle out the answer. He likes an open mind, an observant eye. When Martha Jones' co-worker was crying and freaking out about their hospital suddenly being transported to the surface of the moon in "Smith and Jones," Martha went to open a window, and proved to the Tenth Doctor that she had both the mind and the courage to be a good companion:

Co-Worker: Don't! We'll lose all the air.
Martha: But they're not exactly airtight. If the air was going to get sucked out it would have happened straight away, but it didn't. So how come?
Doctor: Very good point. Brilliant, in fact. What was your name?
Martha: Martha.
Doctor: And it was Jones, wasn't it? Well then, Martha Jones, the question is, how are we still breathing?
Co-Worker: We can't be.
Doctor: Obviously we are, so don't waste my time. Martha, what have we got? Is there a balcony on this floor, or a veranda?
Martha: By the patients' lounge, yeah.
Doctor: Fancy going out?
Martha: Okay.
Doctor: We might die.
Martha: We might not.
Doctor: Good! Come on. [Of the co-worker] Not her, she'd hold us up. 

There's no official job-description for Companion, but we could probably draw up a reasonable list of qualifications. They would look, coincidentally, a lot like the characteristics of the Doctor himself: smart, observant, open-minded, adventurous, inquisitive, unselfish, and—of course—"never cruel or cowardly." 

But there's something else necessary, isn't there? The Doctor meets a lot of people that he likes—smart, decent, capable people—whom he never thinks to invite into the TARDIS. Part of it is the strange alchemy of timing, of course: people have to come into his life at the right moment. But I think a larger factor is wanting. He appreciates a craving for knowledge and adventure. He respects a willingness to step away from an ordinary life. He responds to endless curiosity, and inarticulate longings, and unfulfilled potential. He's the man who stole a TARDIS and ran away to explore the universe, and he has never stopped running, exploring, learning new things. His kindred spirits are people who always long to do—to see, to know, to be—something more. 

Enter Bill Potts. 

"Most people, when they don't understand something, frown. You…smile."

I've written endlessly about what I've called the Moffat Masterplan, executive producer Steven Moffat's long, slow project to turn Doctor Who back into the show it was before it went off the air in 1989. A rising star in television at the time, Moffat had harbored hopes of getting to work on Doctor Who in the late 1980s, but the show was canceled before he got his chance. ("I thought, 'Oh, maybe I’ll get a shot at doing Doctor Who,'" Moffat told The A.V. Club in 2010. "And they more or less axed it that day. It was like I had waited 26 years and missed by an afternoon.") Without ever disparaging the changes his predecessor Russell T. Davies made after rebooting the show in 2005, Moffat has patiently undone most of those changes during his reign: he's brought back Gallifrey, removed the Doctor's overwhelming guilt from the Time War, purged the Doctor/Companion relationship of romantic tension, reinstalled an older man as the Doctor, and made a dozen other big and small changes to restore Doctor Who's original formulae. 

My regular readers know I have been somewhat grumpy about Peter Capaldi's first two seasons in the TARDIS, and part of my frustration was born from impatience with the final tinkering phases of the Moffat Masterplan: I wanted him to declare this long reconstruction project done, and get on with the clean start already. Now, in Moffat's final season, it appears we've finally arrived: both the title and the tone of "The Pilot" suggest that it is a new beginning for Doctor Who, and I couldn't be happier. 

For "The Pilot" feels like it could be Moffat's version of "Rose," Davies' first episode after bringing Doctor Who back from its 16-year "hiatus." (Both Bill's name and her job—serving chips in a school canteen—subtly call back to Billie Piper's Rose Tyler, the first companion of the modern age.) With allowances for modern sensibilities and filming techniques, "The Pilot" even feels like it could plausibly be a direct sequel to the final seasons of the classic era, which happens to be one of my favorite runs in Doctor Who history. Capaldi spent much of his first two seasons being a little too grumpy and dour for my liking, but the Doctor we see here—enigmatic, acerbic, but fundamentally kind and joyful—does not cut a terribly different figure than Sylvester McCoy's sly, gnomic Seventh Doctor.

And, as a companion, Bill Potts seems like she'll be very much in the spirit of Sophie Aldred's Ace: a working class girl, curious, headstrong, with a fresh, slightly irreverent perspective. (Ace, it should be noted, called her Doctor "Professor," a relationship made literal with Bill.) I'd suggest that even Bill's clothes invoke this era of Doctor Who: the patches on Bill's jacket calling back to Ace, and Bill's "Purple Rain" T-shirt summoning the spirit of the '80s. 

And the similarities go deeper: Ace, for example, like Bill, was haunted by her relationship with her mother, which the Doctor led her to confront through the peculiar therapeutic approach of time travel. (His method here—going back to generate shapshots of Bill's mom—is uncharacteristically kind for the Twelfth Doctor, and a lot less manipulative than what the Seventh Doctor did.) And—though Ace was presented as a "tomboy"—there was a strong lesbian sub-text to the journey of self-discovery Ace undertook with the Doctor. Fortunately, what could only be suggested in 1989 can be stated casually in 2017: the Doctor's companion is now an openly gay woman (of color), and I couldn't be happier. 

And, apart from everything else, the character of Bill (and Pearl Mackie's performance) makes a delightful first impression: she answers the "Why me?" question very quickly. "Well, most people, when they don't understand something, frown," the Doctor tells her. "You…smile." This curiosity and open-mindedness is one of the things the Doctor looks for in a companion, and Bill has it in spades. It is she who leaps to sci-fi explanations, when the Doctor is still trying to temper her understanding of what's really happening. ("So you meet a girl with a discolored iris, and your first thought is, 'She might have a lizard in her brain?'" the Doctor says. "I can see I'm gonna have to up my game.") She is endlessly observant, particularly—as we shall discuss more below—about the character of the Doctor, which is something he always needs. She has the thirst for knowledge a companion needs—she comes to the Doctor's attention because she's been auditing his classes—and the longing for change, for travel, for adventure. ("I never go anywhere," she tells him sadly, early in their conversations. And, at the end of the episode, she refuses to let him erase the memory of "the only exciting thing that's ever happened" to her.)

And Bill is endearing: funny, emotionally open, and—refreshing after the brittle confidence of Amy and Clara—somewhat self-deprecating. ("It's all over the place," she says, of her own face. "It's always doing expressions when I want to be enigmatic.") She has a down-to-earth, nonplussed reaction to things, continually puncturing the Doctor's pomposity, which is something else he always needs. "Is this a knockthrough?" she asks of the TARDIS interior, comparing it to a "really posh kitchen." Told that the TARDIS is "the gateway to everything that ever was, or ever can be," her only question is whether she can use the toilet. Running with the Doctor for the first time—the quintessential Companion activity—she can't help but observe that he runs like "a penguin with its arse on fire." (Moffat—who by now has written more awe-inspiring, over-the-top speeches for and about the Doctor than I'm sure even he can stand—seems to relish the opportunity to let a little air out of the overblown sense of wonder.)

"I can't do that anymore! I promised!"

So Bill would appear to be a tailor-made companion. But is it in her best interests to hop on board the TARDIS?

No showrunner in Doctor Who's long history has dealt so deliberately with what it means to be the Doctor's companion as Steven Moffat. In the interest of conserving space, I'm not going to fully back up this assertion here. (See: here, or most other reviews of Doctor Who I've written.) But, ever since he contrasted the childhood wonder of Amelia Pond with the adult bitterness of Amy Pond in "The Eleventh Hour," Moffat has been obsessed with the complicated ramifications of the Doctor's influence on his companions. Amy and Rory had magnificent adventures with the Doctor, but they also sacrificed their child, any semblance of a normal life, and very nearly their marriage along the way. Clara became more and more like the Doctor the longer she traveled with him, becoming both more heroic and more dangerously reckless, until it ultimately cost her her life. (In a bit of a cheat, Moffat got to have his cake and eat it too with Clara: by dying in "Face the Raven," then coming back and getting her own TARDIS in "Hell Bent," she represents both sides of the conundrum: Clara is simultaneously the best- and worst-case-scenario for a Doctor Who companion.) And, while there's no shortage of pseudo- and potential-companions in the Moffat era who have been saved, inspired, and improved by the Doctor's presence in their lives, there are still others—like Lorna in "A Good Man Goes to War," Rita in "The God Complex," and (one version of) Osgood in "Death in Heaven"—who lost their lives when they put too much faith in this madman with a box. 

All of which is to say that Moffat's companions are central to Moffat's project: they are, I would argue, the primary canvas on which he works out his various—sometimes ambiguous—visions of what Doctor Who is. And the themes he is exploring about what the Doctor and his companions mean to each other are often metaphorized in the stories. The tensions between Amy's "normal" life and her life with the Doctor were literalized in Season Five's "Amy's Choice," for example. In Season Six's "The Girl Who Waited," we saw one of those worst-case scenarios play out on-screen, as an alternate version of Amy lost her entire life to the Doctor, becoming a bitter, angry, solitary warrior in the process. After losing Amy and Rory turned the Doctor cold, the adversaries of "The Snowmen" served as thin metaphors for the state of his soul, requiring new companion Clara to help him thaw his icy heart. 

The same sorts of things are happening in "The Pilot": Moffat's themes, tropes, and tricks are pretty much all here, though playing out in a (very welcome) lighter tone. In Moffat's Doctor Who—as the Doctor says of life itself—"everything rhymes."

"Maybe it saw something it needed."

New companion episodes typically keep the plot simple—so as to create plenty of room for Doctor/Companion bonding—and "The Pilot" is not atypical. In fact, its central device is just a variation of a fairly overused idea: abandoned alien technology that becomes obsessed with latching onto unwitting humans. We've seen twists on this trope in "The Empty Child," "The Girl in the Fireplace," and "The Curse of the Black Spot"—to name just a few—and "The Pilot" even recycles the explanation from Gareth Roberts' "The Lodger": that the technology craves a crew, and is drawn specifically to someone who longs to get away. 

But what of it? There's little new under the sun, and I don't object to Doctor Who revisiting ideas, as long as they're as well-executed and thematically resonant as they are here. As in "The Snowmen," the adversary in "The Pilot" is a fairly clever metaphor for the Doctor himself. The Time Lord, we learn, has been lingering at this university for at least 50 years, and perhaps as many as 70. (We don't know why yet: Moffat loves his season-arc mysteries, and I think we can safely assume that the contents of that mysterious vault serve as the teasing riddle of Season Ten.) He has, in short, been lying low for a long time, with no other companion than Nardole (Matt Lucas). 

Where the Doctor's soul was metaphorized as a frozen pond in "The Snowmen," here it becomes an alien oil-slick, long stagnant. "It spent ages lying around being a puddle," he tells Bill. "What changed?" The answer is the same for both Doctor and puddle: each is awakened by a girl with stars in her eyes. "Your friend, she looked into it, didn't she? More than once," the Doctor says. "Maybe it saw something it needed." Heather (Stephanie Hyam) looked into the puddle, and Bill looked into the Doctor: in each case, the object of the gaze responded to the viewer's longing for escape, for adventure, for knowledge, for something more. "Everything wants, everything needs," the Doctor says, and both he and the Pilot found something they needed. "The puddle found a passenger," he says—and he found a companion. 

"She's not chasing you," the Doctor says. "She's inviting you." It's clever, and a nice way for Moffat to keep the theme of the Companion Conundrum in play without hitting it too heavily. The duality between the Doctor and the Pilot represents the polar possibilities—good and bad—that are facing Bill. Bill gets a glimpse of life with Heather towards the end of the episode. "I saw it all for a moment," she says. "Everything out there. She was going to let me fly with her. She was inviting me. But I was too scared." She is, the Doctor tells her, quite right to be scared: there are wonders, but also dangers. "She's making you part of her, and you can never come back," he says of Heather—but he may as well be speaking about traveling with him, too.   

Since the Doctor's memory of Clara was erased at the end of last season, it's unclear just where his mind is these days, but he has clearly processed the notion that he shouldn't be picking up stray humans anymore. And so he pretends to fight the urge. "You're not supposed to get involved," Nardole reminds him, and the Doctor makes a few feints towards pushing Bill away. "Let's get you on the bus," he tells her, when she starts to be drawn into the adventure. "Go be a proper student." He plans to mind-wipe her, until she invokes both Donna and Clara by asking him how he would feel if someone did that to him. (A well-timed snippet of Murray Gold's "Clara's Theme" reinforces the point.) At the end of the episode, at the moment of decision, he tries one last time to resist the temptation of bringing a new companion into the TARDIS. "I can't do that anymore, I promised!" he says. 

But his heart isn't in it. "What, in the end, are any of us looking for?" he has asked earlier. "We're looking for someone who's looking for us." And, really, his resolve was never more than a pretense: the Doctor has been hiding in plain sight all along, as Bill points out several times. She observes, for example, that he has chosen to hide his secret vault—about which he supposedly doesn't want anyone to be curious—in a university. And she has also noticed that his "camouflaged" space-ship is basically a giant set of doors that say "Pull to Open." (They also say "Advice & Assistance Available Immediately," of course: she's got the Doctor's number. Like her face, the Doctor can't help but express his real feelings, even when he tries to be enigmatic.) The parallels between the Doctor and the Pilot play out one last time here: the solution to the problem of the Pilot was to release her from her promise to take Bill along; the solution to the problem of the Doctor is for him to release himself from his promise not to. 

What does it mean for the Doctor to go back on his promise? "It means…what the hell," he says, invoking both Back to the Future's Doc Brown and the spirit of Doctor Who. Because, as much as I have appreciated Steven Moffat's exploration of the sometimes terrible consequences of humans traveling with the Doctor, the Companion Conundrum is ultimately unresolvable. Yes, it is clearly irresponsible and dangerous to keep inviting humans into the TARDIS. (When he tells Bill "You're safe in here and you always will be," he knows—as we do—that he's lying.) But what can he, or Moffat, or the show itself, do? The Doctor needs companions, and so does Doctor Who. The Doctor will never be able to resist the temptation to invite humans to travel with him, and—in spite of the obvious dangers—there aren't very many of us who would resist the temptation to join him. Sometimes, you just have to throw up your hands and say "What the hell?"

So welcome aboard the TARDIS, Bill Potts. We hope you enjoy the ride. 

Additional Thoughts and Favorite Bits

• Welcome back to my sporadically continual coverage of Doctor Who. Time constraints (and occasional grumpiness) led me to be a little sporadic in my reviews of last season, but I'm not about to sit out Moffat's Last Stand. Barring surprises, I'm planning to review the entire season, and I'm resolved to try to be a little more positive this year. (Well, Episode Nine is written by Mark Gatiss: I make no such promises about that episode.) This post is horribly late, but I'll aim to have new reviews up by Sunday evening, or Monday at the latest.

• The "What the hell?" philosophy is actually foreshadowed early in the episode, as Bill randomly recounts the story of a time when she liked a girl so much she fatted her up with extra chips. "That's life isn't it?" Bill says. "Beauty or chips? I like chips." I think even if the Doctor did explain just how physically and spiritually dangerous it was to travel with him, Bill would stick around anyway, because she likes the chips. 

• It's a nice touch that the Doctor has photographs of his wife (River Song) and granddaughter (Susan) on his desk to appear normal, and it makes for a nice set of symbolic bookends reinforcing the clean start "The Pilot" provides. Susan and River were, respectively, the first and last real companions in the previous 54 years of Doctor Who. 

• TARDIS Construction for Dummies: "First, you have to imagine a very big box fitting inside a very small box. Then, you have to make one. It's the second part that people normally get stuck on."

• "Hardly anything is evil," the Doctor says. "But most things are hungry. Hunger looks very like evil from the wrong end of the cutlery."

• It was nice—which is to say, amusing—to see the absurdly costumed, Rick-James clones the Movellans again, as the Doctor takes a side-trip through the 1979 Fourth Doctor adventure "Destiny of the Daleks." 

• If the Doctor is from another planet, why do his people call their space-/time-ships by an acronym that only works in English? "People don't generally bring that up," the Doctor admits. 

• Nardole pretty much summarizes the Companion Conundrum at the end of the episode: "That's the Doctor for you: never notices the tears."

NEXT: Episode 10×02 – "Smile"
Read all my Doctor Who reviews here.