The crowd is enraptured by Ashildr. Bill isn't sure she's ever seen or heard a crowd as silent as this one. Ashildr's strange, husky voice echoes and loops through the air, creating its own counterpoint, and the audience applaud louder and louder with each song that finishes.

When Ashildr finally finishes their set and bids them all goodnight, the crowd is deafening.

Ashildr has their new audience, alright.

It takes a small while to get the stage prepped for Event Horizon, and Bill gets her mic checked with a technician in the meantime.

"How are you feeling?" Theo asks her from nearby, where he is also getting seen to.

Bill swallows. "Like I've swallowed a hyperactive hamster that also has anxiety." From nearby, she hears Missy snicker at that. "But, you know, fine, really. I know we can do this. I just hope that if - when she's not there, it doesn't throw me off."

"If she's not here," Theo says, coming to put a hand on her shoulder, "it just means she's a normal person who can't afford to follow a band across the entire world night after night."

"You know, as opposed to a weird, possibly incredibly rich stalker," Missy interjects from a few metres away.

"Or criminal," Nardole adds, thoughtfully. "She could be hacking her way into tickets."

Psi, one of their senior technicians, looks up from his laptop. "No, she really couldn't be," he says, looking vastly offended by the mere thought.

"Overconfidence is nobody's friend, Psi Boy," Missy tells him, rolling her eyes. The sci-fi nerd in Bill takes a moment to appreciate the Princess Leia inspired nickname she has for him. "I've hacked into your system twice, when I was bored."

"Only twice? I've done it at least six," Nardole replies.

Missy waves her hand at him. "Overconfidence is even less attractive on you, Eggman."

"Hurtful," Nardole mutters, before rolling his eyes. "Or it would be, if I cared what you think, which I don't, because you're fifty one shades of bonkers."

"But I wear them so well," Missy says, with a smile and a flourish of her hand.

Theo is meanwhile looking at his phone. "River and her lot are wishing us luck. Helen apparently is rooting for Bill and her girl."

"Tell them thanks," Bill says, feeling vaguely reassured just from hearing that.

She checks the general Event Horizon tag on Twitter in the last moments she has with her phone before they'll all have to hand them over to the crew. She scrolls down a bit to get ones starting from before the concert. Immediately, she feels wonderfully overwhelmed by the dozens upon dozens of tweets.

horizongal - finally getting to see Event Horizon tonight! My life is about to be made

songsmithfy - probably going to die from being so close to -thedoctor in the flesh but whatever it's fine it'll be worth it

crystal_ss - concerts are Not My Thing but I hope things go awesomely for everyone tonight! I know -EventHorizon are going to nail it

riversong - our side of the world already feels more dull for EventHorizon having left it. Wishing them all the best of luck with their show tonight xx

riversong (replying to riversong) - also, America, prepare to be positively enthralled by -Ashildr and their utterly unique presence, you're in for a treat!

punkprincess - like -RiverSong said, all of us in the UK are rooting for -EventHorizon right now! but we miss you already [heart emoji]

actualellewoods - -RiverSong always coming through and speaking our minds! I'm not in the UK but all of us non-US fans are cheering you on via internet

queenbaloo (replying to actualellewoods) - -actualellewoods and I are having our own afternoon -EventHorizon dance party to make up for being stuck in Actual Narnia

actualellewoods (replying to queenbaloo) - we're there with you guys in spirit

stirmypotsy - wish I could be there with -EventHorizon tonight! wishing I could see my girl -pottsalotts IRL [crying emoji]

Bill finds herself grinning at her phone. Their fans never fail to make her smile, and often when she most needs it. The sheer number of different people is a bit overwhelming, but certain names have started sticking out after a while, some of the more hardcore fans who are actively involved in any possible Event Horizon development and must have every member of the band as well as Ashildr and maybe River on Twitter notifications.

She checks the most recent tweets. Sure enough, people are going nuts for Ashildr.

amatalefay - oh my god that was amazing I've never seen anything like it

horizongal - um holy shit so Ashildr's EP is great and all but there is NO substitute for hearing them live? I'm shook?

spaceacepupper (replying to horizongal) - ever since I saw them in Glasgow I've been wondering if they're even a creature from the mortal plane

pottsalotts (replying to spaceacepupper) - I've known Ash for like a year now and I'm still convinced they're some kind of ethereal being tbh and they just laugh weirdly whenever I mention this

spaceacepupper (replying to pottsalotts) - Ashildr is merely blessing us mere mortals with their brief presence on this plane, this is now Bill Potts confirmed (also Bill hi ily!)

pottsalotts (replying to spaceacepupper) - [heart emoji]

There are dozens of other tweets praising Ashildr, more pouring in by the second. Bill sends Ashildr a quick text with her congratulations before her phone is taken from her by an unamused Kate Stewart, who has been apparently trying to get her attention for the last two minutes.

"Sorry," Bill says.

Kate remains unimpressed, but given that Kate's entire power suit lesbian aesthetic is a slight weakness of Bill's, Bill doesn't have any complaints about being on the receiving end of that look. (Is Kate single? Bill is suddenly wondering if she rightly remembers her mentioning have a girlfriend who is a surgeon. Was that a weird gay dream Bill had had?)

"Bill," Missy says, touching her on the arm and making her jump. "You're in confused gay daydream land, poppet. Best hop out of there for now, hmm? Got a proper girl to impress this time. And, you know, a whole crowd, possibly don't want to forget about them."

"Yeah, that," Bill says sheepishly.

The lights on the stage are up now, and the crowd is cheering for them, and Bill can feel the stage adrenaline begin to build.

"Okay, let's do it," she says to the other three.

They head out onstage, to thunderous applause, and take up their positions.

"Good evening Los Angeles!" Theo says into the microphone, and gets deafening screams in response.

Bill takes this time to try and search the front of the crowd for the Star Girl. Her heart is pounding in her chest, and she feels a bit like she might be sick, or like that hamster in her gut is having a panic of its own.

She almost misses her - but sure enough, there she is. Fluffy blonde hair, those bright eyes staring up at her, and a big smile that gets wider as Bill's gaze lands on her. She gives Bill a little sheepish look, and Bill wishes she could think of something cool or smooth or something good in response, but she can't. Her heart has actually skipped several beats.

Luckily, her ears still pick up on Nardole's drum beat and she snaps back to attention, coming in with the bassline on time, just.

She's sure she's never grinned so hard while playing as she does while standing on this stage and playing her heart out for Star Girl, who apparently is willing to follow her across the ocean.

The moment they come offstage, Bill finds herself being twirled around by Missy in a strange, manic waltz.

"So, Miss Potts, you've successfully managed to charm a girl into following you all the way around the world, what are you going to do next?" Missy asks. Bill laughs nervously, still so giddy from the performance and from seeing the Star Girl that she barely knows how to get words out. "Please say that you're planning on finding a way to lovingly bang her brains out, or I may have to disown you as a friend."

"Okay, moment over, you ruined it," Bill says, pushing out of her grasp and making a face.

"What? She's cute, Pottsie, I'm being supportive," Missy says, blinking at her.

"Don't sully this."

"Bringing sex into it doesn't make it cheap by default, you know," Missy replies, rolling her eyes. "I did use the word lovingly for a reason."

"Bill! Your girl! I saw her! She was really here!" Nardole, who has appeared from nowhere, grabs Bill's arms, his round face alight with genuine excitement, and Bill feels the giddiness rise again.

"I know!" Bill says, grabbing his arms in return, and the two of them jump up in down in a circle like babbling idiots until Theo and Clara walk in.

"Hey, congratulations," Clara says to Bill, and gives her a big hug. "It's a pretty bizarre situation, but I'm definitely rooting for you."

Theo, meanwhile, looks at Bill with the hint of a smile in the corner of his mouth. "Bill, I think it's time."

"Time for what?" Bill asks, without really thinking.

"Time we heard your song."

Bill knows these are her friends. Her family. She knows they would never belittle her, that they think the world of her. That doesn't mean she isn't terrified to play them this song. Theo, Missy and Ashildr are songwriting geniuses, how could she ever measure up?

"Go on," Missy says to her gently, from where she, Clara, Nardole and Ashildr are sitting in the hotel suite's comfortable chairs in front of her.

Bill nods, takes a deep breath, and looks to Theo, who has taken the chord sheet she's given him and looked over it and now gives her a nod in return. It won't be a perfect playthrough, but he's good enough at what he does that it'll be fine.

Bill nods back, and he starts to strum, and she starts her bassline. Then she starts to sing.

It's called Promise You Won't Go. And by the time she sings the last line, Clara is wiping away a tear that had gathered in her eye, and Missy's eyes are shining with a fierce pride.

"That was wonderful, Bill," Ashildr tells her, and Bill lets out the breath she had been holding.

"I've already got a lot of ideas," Nardole adds, his fingers drumming on his thighs with great purpose, filling Bill with an excitement about how the song might sound with all the parts filled out.

"As do I," Missy says. "God, you've made me feel proper emotions, Pottsie. That's disgusting. How dare you."

Bill laughs a little, and looks to Theo, whose pride is softer than Missy's but no less powerful. His eyes are warm as he pulls her into a one armed hugged and kisses the side of her head.

"It's brilliant," he murmurs. "You're brilliant. I always knew you had this in you."

Bill can't help the tears that come up at that, and she puts her bass down so that she can hug him tightly. She's never known her biological father, and she's come to be glad of it, because Theodore Smith is the only father-figure of any kind that she could ever need.

They spend the whole trip to the next city - is it San Diego? Bill has no idea, she's so focused on her song that everything else has faded from her mind - working on the group arrangement of Promise You Won't Go.

"We could put this on a deluxe edition on the album, if it goes down well," Nardole points out.

"When it's received as an absolute delight, yes," Missy retorts.

By the time they arrive, it's sounding amazing and Bill can't believe that she's so blessed as to have these people for coworkers and friends and family. It's overwhelming and she feels a bit like she might be sick from nerves, but she's also excited as all hell.

She's Bill Potts, and she's about to woo the pretty girl that has been making her stomach do backflips for weeks. She's never felt as powerful, or as anxious.

pottsalotts - got a surprise for you lot tonight xx

Unsurprisingly, Twitter goes nuts at that, several of her fans correctly theorising that she's going to play the gay song she's been working on. She hopes she lives up to their excitement.

queenbaloo - I'm not gonna lie Bill Potts could stand up there and shriek into a microphone for three minutes and I'd still think it was beautiful

missymasters (replying to queenbaloo) - you and me both, but they all looked at me weirdly when I suggested that as a wooing technique

queenbaloo (replying to missymasters) - ashdkglh

Bill's asked if she can speak briefly, before they play the song, and she spends most of the day going over and over it in her head, working out how to make a grand gesture without looking like a total idiot.

While Ashildr is onstage doing their set, and Bill thinks she might actually explode before she gets onstage, a hand slips into hers at just the right moment and gives it a tight squeeze.

Bill looks to her right to see Missy sitting next to her.

"Don't worry, kiddo, you've got this," she says. "She'd have to be an idiot to not want to marry you on the spot, with a song like that."

Bill smiles a little and nudges her shoulder. "Thanks."

"Also, remind me to never call you kiddo again. Too weird."

"Why?"

"Because I've thought about having sex with you far too many times for that to not be wildly inappropriate," Missy replies, shrugging, and Bill somehow chokes on her own saliva at that. "Anyway, I'll let you get your mic sorted, I think we're on a sec."

"Stop just saying things like that," Bill calls after her, trying to remember how to breathe. "You're going to make me have an actual, honest to god lesbian heart attack."

Missy just winks at her over her shoulder, and Bill takes several deep breaths and fumbles for her water bottle. Now is not the time for this.

They head on stage and sure enough, there's Star Girl again, and the relief in Bill's chest is overwhelming. She knows the absurdly relieved smile she gives is probably betraying her feelings far too much, but given what she's about to do, that's not so bad.

God, she's so beautiful. It's hard for Bill to focus on playing their other songs, because she's so curious about why her smile is so guarded and yet so genuine, about why her eye looks like that, about why she comes to every single show when it must disrupt her entire life to do so.

About whether it all means that maybe, just maybe, she feels the same way about Bill.

Partway through their set, when the atmosphere is so uplifting and and electric, it's time.

"Now, as it happens, we have a bit of a surprise for you tonight," Theo tells the crowd, "and I'm going to hand things over to Bill."

Bill and Theo swap places, but Bill makes sure she can still see Star Girl. She's further away from her now, but not by too much. Star Girl's face is unreadable as she watches Bill.

"Hey, everyone," Bill says nervously. "It might actually shock some of you guys that I'm not super great with talking in front of crowds. I'm probably in the wrong job, to be honest."

She sees a lot of the teenage girls in the front row fervently shaking their heads, and many are screaming words of encouragement at her. It's so wonderfully sweet that Bill finds herself smiling.

"Except I'm not, because you guys are amazing and make it absolutely worth how nervous I am right now," Bill continues. "I know at least some of you know that I've been trying to write a song. Well, I did it. I wrote a song. For a girl. A beautiful girl who is a total enigma to me."

She finds Star Girl's eyes as she says this. Still, she can't quite read her face, but her eyes are shining.

"Anyway, this might be the most insane thing I've ever done, but god, I hope it works," Bill says. "It's called Promise You Won't Go."

The song starts, and the whole audience is quiet and awed. Bill tries to find a good balance between looking at Star Girl as she sings and looking at the rest of the audience. Star Girl seems stricken, her eyes wide and shining as the song continues.

Finally, it's the last line.

"I don't know you but it's only you, and I hope you know, so please promise you won't go."

Star Girl is biting her lip, hard, eyes full of emotion. Bill gives her a breathless little half-smile, a question of some kind, a plea.

The crowd erupts into deafening applause, and Bill turns to look out at them all, not able to neglect them even in this moment. She loves them all so much. They make her feel so special, and they're all so special themselves, in their own ways.

Once she feels she's given it enough time, she looks back to Star Girl, only to find her gone. Bill can't help the rush of disappointment in her chest, but recalls the time that she'd moved around when Bill had stared at her too long one time before. Well, Bill had certainly overdone it this time. No wonder she can't see her, people are probably super suspicious right now.

The last thing she wants to do is bring heat down on Star Girl, with how intense their fandom can be. She'll have to be more careful, going forward. She can't see Star Girl anywhere, so she must have moved considerably further back. Bill can't be angry, only disappointed, because she understands why.

It's not too difficult to let the rest of the concert distract her, throwing herself into the music and the faces of her other fans, looking up at her with such wonder and hope.

When she comes offstage, she is bombarded with congratulations from all of the crew, from Clara and Ashildr, and of course her bandmates.

"So?" Missy asks.

"I dunno, I lost sight of her," Bill says, still feeling giddy. "I think she ducked out to avoid getting people's attention, you know? I was staring at her way too much, and she's kind of distinctive with her eye - oh god, I haven't just landed her in a pile of shit, have I? Our fandom is insane-"

Missy stops her mouth with her finger. "I'm sure it's fine, Pottsie. People noticed, but it's dark in those mosh pits, they wouldn't have gotten a good look at her."

"Yeah, you're right," Bill agrees, taking a deep breath and grinning. "Well, I did it!"

"Now we wait to see what happens next time," Nardole says, also grinning. "This is quite exciting, isn't it? Like in a film."

"That implies a film would be this good or feature an interracial sapphic romance, so no, it's not like a film, it's better," Missy tells him, making Ashildr and Theo snort nearby.

Bill isn't sure what is going to happen next, but she feels like she's on clouds.

A recording of the song makes its way onto YouTube immediately, of course. It has hundreds of thousands of views within a day. Luckily, the verdict seems to be that everyone loves the song. The link to the video has been retweeted thousands of times, and a good quarter of the reactions are just the crying emojis from emotional gay teenagers.

pottsforpresident - oh my god she was singing to somebody in the audience DID ANYONE SEE WHO IT WAS

yikes_lou - why did the gay love song not end with the girl getting pulled on stage so they could make out, we've been robbed

yikes_lou (replying to yikes_lou) - more importantly BILL has been robbed we better be hearing about her new gf soon bc I swear to god if this doesn't land her the gf

spacedracula - Promise You Won't Go is one of the best love songs I've heard in ages - achingly genuine in that uniquely Bill Potts way.

starsthemselves - I swear I've been in this fandom for like five minutes and this happens, this is wild but I love it and love Bill so WOO

rainbowrosie - will your fave ever be as iconic as actual lesbian goddess sent to us by Sappho herself Bill Potts? No

The last one makes a strange noise escape from Bill's chest, something between a laugh and a sob, because it's such an absurd idea but to think that people see her like that, that these girls see her like that, is so much. Too much. It's a wonderful kind of too much, though.

A part of her does just want to scream that she's as normal and disastrous as the rest of them, though. Today that part is louder than usual, and she knows it won't be quiet until she sees Star Girl, until Star Girl smiles at her.

Chest filled with nerves, Bill steps out onto the stage for the next show, wondering what kind of read she might be able to get on Star Girl, wondering how she can convince her to come backstage without being able to talk to her. Wanting to get a proper look at her since playing her the song, since she hadn't been able to last time.

She isn't there.

Bill tries not to think about the connotations of that, can't let herself, not when she has a concert to help put on. She searches the faces in front of her desperately, but to no avail, and ignores the way her stomach feels like it has a boulder inside it.

She wants to cry. She doesn't.

She sings, she keeps her eyes on her fretboard, she smiles at the crowd at the end even though it's hard to do so, even though she wants to cry.

When she comes offstage, everyone there is looking at her with bated breath.

"I don't-" Bill swallows. "I-"

The tears finally come out, and she finds herself being hugged fiercely by Missy, with Nardole coming around to hug her from the side, and Theo wrapping his arms around all of them. She's never felt more loved, more supported, and yet, she can't feel happy, not even a little bit.

"She might come tomorrow," Nardole says hopefully.

Bill just cries and holds them all tighter. "I messed it up. I don't know what I was supposed to do, but I messed it up."

"I can't believe I'm saying this, but the Eggman is right," Missy tells her. "She might just need some time to think it over. Don't give up on her yet."

Bill tries to believe her, tries to keep hope.

But the Star Girl isn't at the next concert either. Or the one after that. Or the one after that.