A/N: Erm, so I saw Ghostbusters five times (two more since I first wrote this, moving it over from AO3) and I couldn't really move forward with my life until I got this out of my head. Apparently my specialty is injecting angst into everything, even fandoms of comedies that don't need this nonsense.

I've been binging on a lot of GB fic lately, and came across a couple stories where Rebecca Gorin and Holtzmann had a history, so obviously that headcanon isn't originally/solely mine. I just couldn't stop thinking about a different take on the aftermath of her visit at the end of the movie.

"I'm ba-aaaaack."

There is a certain ridiculousness to (sort of) quoting Poltergeist to a bunch of real life ghostbusters, but no one seems to care about the irony as Jillian Holtzmann waltzes back into the firehouse and their lives, dropping two duffle bags unceremoniously on the floor.

Patty lets out a whoop of delight at her appearance and Abby grins hugely, both of them on their feet and hurrying to hug the prodigal engineer. Holtzmann resists, instead doing an uncanny impression of an audience member chosen to play The Price is Right, jogging in tight loops and reaching out for high fives.

At some point she starts shadow boxing, and it turns into more of a Rocky thing.

"Can't believe how much I actually missed this nonsense," Patty tells her, forcing a sideways hug on Holtzmann.

Abby hugs her next, a grin splitting her face and already talking ghost business in Holtzmann's ear. "You should've told us you were coming! We had a truly excellent bust this morning, but we coulda waited."

"Dahling, you know I like to make an entrance."

Erin hasn't moved.

She's standing at a whiteboard with a red marker in her hand, staring at Holtzmann like she's some sort of apparition.

The other three stand in a knot for a moment, Patty affectionately rubbing Holtz's hair while Abby tries to catch her up on every actual apparition they've seen in the past six weeks and still Erin doesn't move.

Patty notices first, glancing over and giving her a wide eyed, aren't-you-gonna-say-hi? sort of head jerk.

"Jillian," she intones loudly, the syllables sharpened on her teeth.

It effectively quiets the conversation, and Holtzmann turns toward her. "Dr. Gilbert," she parrots, dipping the pitch her voice and giving a satirical little bow, and just like that fury roars to life in Erin's gut because this isn't freaking funny.

Erin folds her arms so no one sees her hands shaking. "So, what, are you on vacation or something?"

Holtzmann's posture formalizes a little, leftover smirk draining from her eyes as she says, "Actually, I was hoping we could get the band back together."

Patty's eyes light up. "For real? It ain't even been two months!"

Though she looks similarly pleased, Abby clarifies, "Gorin's project done already?"

"Mmm-hmm." Holtzmann turns to Abby, bringing her heels together and giving a dramatic two finger salute. "Put me in, coach!"

Abby and Patty erupt into exclamations of excitement.

"This is amazing!"

"OG Ghostbusters, together again!"

"We've still got your uniform - "

"My proton gun's been making a noise I've been meaning to call you about - "

"NO."

Erin's voice falls like a cleaver, ruining their fun. Two pairs of eyes swing toward her; Holtzmann just looks at the ground.

"Are you kidding me? She...she can't just waltz back in here, she left us." Her voice breaks on the us, like the word might crack right open and reveal Erin really means me.

"Erin," Abby's using her patient, talking-Erin-back-from-an-edge tone. "She got a prestigious career opportunity. Temporarily. You of all people - "

"No, no, no, it's not the same." The pitch of her voice is climbing rapidly toward hysteria; any second now and Erin will be stomping her foot like a toddler. "We hunt ghosts for a living, nothing Caltech sanctioned could be better than that. It wasn't about the work, she left us." Me. "She chose someone else over us." Me me me, she didn't pick me.

Thick, uncomfortable silence envelopes them. Holtzmann lifts her gaze to look at Erin, but there's nothing to read in her expression. Not guilt, or defenses, certainly not apologies. She is big eyed and beautiful, and uncharacteristically still, like she's jut going to stand there and wait for more, like she's just going to take it.

Erin can't look at her anymore, so she makes defiant eye contact with both Patty and Abby, exclaiming, "She's not even denying it!"

Then she turns on her heel and walks away just before the tears in her eyes brim over.

"Just give her some time," she hears Abby saying when she's halfway up the stairs. "She...took it hard when you left."

Six Weeks Ago

Erin only stomachs about half an hour of their going away party for Holtzmann before she slips away to the roof to have a pity party for one.

Still, for only spending thirty minutes at the gathering, she managed to get impressively tipsy, has been downing red wine like it's morphine for the ache in her chest that hasn't gone away for the past week, ever since Holtzmann told them she's leaving.

At the moment, Erin's almost angrier at Patty and Abby than at Holtzmann. She doesn't understand how they're so okay with this, how they're so happy for her, acting like it's anything less than a betrayal. Just because Holtz's old professor and mentor showed up out of nowhere, and after two weeks of walking around the engineer's lab like she owns the place, she'd invited Holtzmann to accompany her to California, to work on some top secret project she'd just won a massive grant for.

And Holtzmann actually said yes.

Erin's barely spoken to her since. She's saved all her fighting for Abby.

"Isn't that the first thing you told me about her? That she was loyal? So much for that."

"Hey, go a little easy on her," Abby had replied, her expression equal parts sympathetic and admonishing. "It's not forever. And she's right, the busting's a well oiled machine at this point...there's not as much need for Holtzmann to make us new stuff all the time. We've got the new book, Patty's got classes for her Masters. Holtzmann deserves to have something fresh to work on, too."

Now, Erin leans on the edge of the roof and looks out over the city; the thanks and tributes to the ghostbusters are long gone, the lights empty and meaningless.

The door to the roof opens and music comes bouncing through it, hitting Erin from behind and breaking a long silence. It's Tears for Fears, "Everybody Wants to Rule the World", and a whole verse passes without her turning around before Holtzmann finally calls over the song, "You were missing the dance party, so I brought it to you."

Holtzmann's holding her ancient boom box and rocking her body back and forth in time to the song; the dance most closely resembles jumping jacks, but only lifting one side of limbs at a time. It occurs to Erin that the lab is now going to be empty of Holtzmann's music and Holtzmann's dancing. She has to look away.

Holtz sets the boom box down, leaving it on, and struts over to join her. "Chin up," she says, bumping her shoulder against Erin's and throwing her a trademark wink when she glances over. "You'll still have Kevin for eye candy around the 'ol firehouse."

She doesn't say it like a dig, but Erin wouldn't be surprised if this is the only way Holtzmann can insult someone: grinning all the way. She bristles, shuffling deliberately away from the other woman. "At least Kevin never abandoned us," she murmurs childishly, courtesy of the wine coating the anger and hurt rushing through her veins.

The smile leaves Holtzmann's eyes, but her lips stayed curved upward. "Wellllp," she muses, dragging the L and popping the P. "Debatable. Depends on how much you think 'intent' matters in abandonment. That time he got lost for five days playing Hide and Seek was sort of an abandonment. End result wise, anyway. There was no one to answer 30% of the phone calls."

"This isn't funny," Erin says between her teeth, a thickness in her voice that wasn't there a moment ago.

It actually earns her nearly a full minute of quiet before Holtzmann says, "It's just for a year. Maybe less, if we finish - "

"And then what?" Erin demands, rounding on her, because she's so sick of no one actually saying what this is really about. "You and Dr. Gorin move back into the firehouse together?" Off Holtzmann's genuine surprise, Erin smugly adds, "She wore a wedding ring in her old Facebook photos but she isn't now. So. Not hard to figure out why you want to go."

Holtzmann looks put out, like she doesn't want to be figured out so easily from such circumstantial evidence, but Erin's leaving out the crucial part: she's seen the way Holtz looks at Gorin. And Erin knows that look.

It's some version of the way Holtzmann looks at her.

Holtzmann's being so quiet, now, and still; it's disconcerting. The moment feels stretched out and unbearable, she just wants out of it. So Erin pushes her weight off the wall and takes a step back, like she's about to leave. "Guess that toast you made to us was kind of bullshit, huh?'

It's a mean, deliberate shot, and it lands, Holtzmann's face pinching and filling with hurt. That's what Erin wanted, it's the whole reason she said it, but she still feels all-of-a-sudden awful, like she just crumpled up a good memory, leaving it creased and ruined forever.

Holtzmann scrutinizes Erin, her stare tight and calculating.

Then, with deliberate swiftness, Holtz seizes the front of Erin's blazer and yanks her close, crashing their lips together.

It's a hard, scorching kiss, and it's over too soon, leaving Erin singed at the edges and struggling for breath.

"What...what was that for?"

"I figured you couldn't get any angrier at me than you already were," Holtzmann says calmly, though there's something disheveled in her expression. Mostly in the eyes. "So it seemed like a good time to finally try that."

Erin exhales a tremulous breath. "You thought that would make me angry?"

Then they're kissing again.

"So what're we feeling for dinner? Is it pizza's turn? I think it's pizza's turn."

"Perfect."

"Right-o, boss."

Abby looks at Erin expectantly. "Erin? Pizza good with you?"

Her best friend is already heading for the stairs. "I'm okay, thanks."

Abby and Patty exchange a look. Patty speaks up, "C'mon, girl, you gotta eat, too."

Erin doesn't even glance back, her voice thin and distant. "I'm really not hungry. You guys go ahead."

As she disappears, Abby can't help but glance over at Holtzmann. The engineer wears sadness like a cartoon character, her body practically sagging with the physical weight of it. Abby halfway expects bright red broken hearts to appear over her head any day now, matching the wounded pout on her face.

She's been back nearly two weeks, and Abby's getting tired of seeing that expression.

"You know what?" she says suddenly, loud and declarative. "I'm going to go have a talk with her. The sulky act is getting a little old, and you'd think Erin would be more forgiving, considering we welcomed her back - "

"Wait."

Abby's halfway to the stairs, riding on righteous indignation, but Holtzmann's voice, small and pained, stops her. She turns around, waiting.

Bouncing nervously on the balls of her feet, her hands rubbing pointlessly together like they're craving a blow torch or something else to wave around, Holtzmann says, "There is a strong possibility you're lacking some critical information here. About why Erin's mad."

Abby and Patty look at each other again; Abby can see in the other woman's expression she has the same suspicion. "What happened, Holtz?"

"You should maybe ask Erin - "

"Nuh-uh, baby, you can't just say something like that and then not follow up," Patty declares impatiently. "No secrets in this family."

Holtzmann aims her eyes at the ceiling and sighs, then practically recites, "The night before I left with Dr. Gorin I kissed Erin on the roof."

Silence follows this pronouncement, eventually broken by Patty. "Like...a goodbye kiss?"

"I...don't think that was the message conveyed."

Abby winces, a dark sort of guilt pooling in her stomach, warring with an obscure, selfish hurt that Erin didn't tell her herself.

"It's okay if you think I should leave," Holtzmann says, her vioce uncharacteristically small. "Just don't be mad at Erin."

Erin's sitting on the floor of her bedroom eating a sad looking sandwich of just turkey, by itself on wheat bread. It's the best she could do from the smaller, upstairs kitchen, and she's trying not to think about the pizza that's probably been delivered by now. She'll sneak down later, after everyone's in bed, and see if Patty left her a few slices in the "Erin" labeled drawer of the fridge; she does that sometimes.

Abby, on the other hand, refuses to enable Erin skipping group meals, so it's a surprise when the bedroom door opens a crack and Erin's best friend peeks inside, brandishing a plate of pizza like an olive branch. "Brought ya a treat."

Skeptical, Erin raises her eyebrows. "What's the catch?"

"Nothin'." Abby eases further into the room, shutting the door behind her. "But I do miss you at meals. Can I sit?"

Erin nods, still wary but unable to resist the smell of pizza. She drops her sad sandwich immediately and accepts the plate from Abby.

Settling beside her on the floor, both of them leaning back against the bed frame, Abby wastes no time. "So I'm sorry."

It's about the last thing Erin's expecting. "You're sorry?" She's almost always the one who has to apologize in this friendship. Abby doesn't have the same tendency to screw up.

"Yeah. I haven't been very understanding with you lately. I know I've been dismissive of your feelings." Abby pauses. "Holtzmann told us what happened."

Erin groans, appetite suddenly deserting her as she puts the plate down in favor of hiding her face in her hands. "She shouldn't have done that."

She feels Abby tug gently at her sleeve. "I wish you had told me."

Slowly, Erin uncovers her face and looks at her best friend. Abby's face has gone soft at the edges, sympathetic and patient and so damn familiar it makes Erin want to cry.

She's wanted to tell her a million times over the past two months, but shame tripped her up every time. Now, though, Abby knows and that makes it easy to just admit it, the first time she's heard it out loud. "Holtz kissed me."

It sounds so small and childish, like she's thirteen years old (not that Erin was being kissed at thirteen, or at most ages, actually), getting this hung up on just a kiss. Except there's no just, there never was with Holtzmann. Erin shakes her head a little, frustrated, not sure how to explain it, all the tiny moments and flirtations that sound inadequate in the retelling, but the whole had been greater than the sum of their parts. At least, it had felt greater. It's like Erin had been reading promises in Holtz's eyes, maybes and almosts that she'd really, truly believed would be fulfilled.

The kiss on the rooftop - no, kisses, plural - had felt like the culmination of every almost they'd had. It had felt like the start of something, not the end.

But Holtzmann left anyway.

"It wasn't just the kiss," Erin explains. She can hear herself starting to cry, and for once she tries not to care because Abby's hand slips warm and comforting over hers. "For months before that, it was like something was...I really thought..."

"I know," Abby interrupts gently, because she still knows her so well and she knows sometimes words about her feelings get all tangled and messy in Erin's throat. "We all thought it."

"You did?"

"Yeah. Well, Patty and I did. I guess I can't speak for Kevin...he might've missed something even that obvious."

Erin lets out a wet laugh, wipes her eyes with her sleeve. "You guys were coming upstairs with the cake, remember? We moved away before we got caught and then I didn't talk to her alone again...and I woke up the next morning and she'd left for her flight." Her voice shrinks, "And when I woke up...I thought she must've decided to stay."

"She screwed up. And you should be mad about that," Abby agrees, and it means more than Erin would have expected. "But, Erin...she did come back. Doesn't a big part of you want to know why?" When Erin doesn't say anything, Abby just nods. "Be pissed for as long as you need, okay? I get it. But...she can't start to make it right until you decide to let her."

"You laughed."

Startled, Erin turns away from the refrigerator to see Holtzmann standing on the other side of the kitchen island, looking right at her. She's still in her coveralls from the job, her goggles pushed up on her forehead, and she's looking directly at Erin.

She hasn't tried to engage her like this, so direct, since the first day she got back, over a month ago now, and it renders Erin instantly frazzled.

And angry. Right, yeah, she's still so angry.

"What?" The word comes out clipped and impatient, making it clear she doesn't want to talk, that this still isn't okay.

"You laughed," Holtzmann repeats in a matter of fact tone. "Earlier, in the Ecto 2.0. During my dazzling performance. You laughed."

"Did I?" Erin mutters vaguely, turning her back on Holtzmann and ostentatiously perusing the fridge, hoping the engineer will just take the hint and leave.

The thing is, Erin knows she laughed. She couldn't help it, watching Holtzmann in the front street, driving a tricked out hearse through the streets of New York City while she sang passionately along to the radio and 99 Luftballoons. The German version, though Holtzmann had attacked the lyrics with such gusto that it took a moment to realize she was mostly throwing together nonsense syllables.

Buzzing with adrenaline of a successful bust, with Abby and Patty's howls of mirth filling the space of the car, Erin's own chuckles had erupted from deep in her chest, the tender open spot where happiness always hits first. She'd kept it quiet, though, thought herself safely hidden in the distant backseat. She hadn't thought Holtzmann would notice.

She kind of thought Holtz had stopped paying attention to her.

"Yes." There's something oddly formal about Holtzmann's voice, and Erin can't help but turn back, catches her rocking slightly on the balls of her feet, hands folded primly in front of her. An orator's pose. "And three days ago you got out four mugs when you were making coffee, including the X-Files one which you know I like best. And you've called me Holtz instead of Holtzmann five times in the past two weeks. But I still wasn't sure, but then today you laughed and I thought possibly sorta maybe."

"Maybe what?"

"Maybe that means you're finished hating me."

She's so earnest. Holtzmann's voice sounds like something freshly hatched, something that never learned to lie or manipulate or conceal. Just hope, laid bare.

It makes Erin's chest hurt. It makes her honest, as she blurts out a reply, "I don't hate you."

There's more clinging to the end of that sentence - I never did, I couldn't, I tried really hard - but Erin catches it behind her teeth and swallows it down, back to the pit of her stomach where so much unspoken truth lives.

It's such a small concession to make, the lack of hatred toward someone she once considered family, but Holtzmann grins anyway, this brilliant smile that scatters light across her face. "Great!" She claps her hands together, fingers fluttering. "So I can finally give my speech."

"What do you mean finally?"

"I've had a speech ready since I got back, the flight here is five hours and twenty minutes, so I had it easily memorized by the time I landed. But Abby knows you best and she said to give you space, so I've been waiting until you don't hate me anymore but then you laughed so here goes nothin'."

Holtzmann doesn't seem to be waiting for further permission, just takes a formal, oratory breath and then begins, "You told me when you were eight years old you saw your neighbor's ghost in your room and you believed it was real even though everyone thought you were wrong it seemed like a bonkers thing to believe in people made you feel crazy but you went on believing because you were sure you were right."

It's just like that day in the bar, after they saved the city, Holtzmann's speech launching out of her like a bullet train, punctuation dictated by her need to take a breath rather than any grammatical consideration.

"When we first met you were living life claiming not to believe in ghosts you'd wanted nothing to do with that for years but you came with Abby and I inside the Aldridge mansion anyway because you couldn't resist the chance to prove you were right about the crazy thing you believed all those years ago well for me the crazy thing I believed was that Dr. Rebecca Gorin and I were meant to be together."

It's not a surprise, so it shouldn't knock the wind out of her, hearing it stated so plainly like that, but it does, and it must show in Erin's face because Holtzmann actually falters, stepping closer and reclaiming eye contact before she continues.

"She was married and she was my professor and we only slept together seventeen times in two years, she didn't make any promises or ever bring up leaving her husband so there was no evidence whatsoever to support my belief but I believed it anyway. And I hadn't really for years and years before she showed up here and even though it had been so long since I'd had feelings for her or even thought about her much I still couldn't resist the chance to see if I was right just like you came into the Aldridge mansion with us except mine was a lot dumber because you had visual proof of a ghost and I never saw anything to suggest Dr. Gorin and I should be together and that's why you were proven right whereas I turned out to be very very wrong."

That seems to end the speech; Holtzmann looks spent with the effort.

It takes Erin a moment to really absorb this, emotions wrestling in her chest with no clear frontrunner until she finds herself wondering about how Holtzmann discovered she was very, very wrong.

"She hurt you again?" Erin asks quietly, understanding that hurt the first time around was implied. She pictures Dr. Gorin's face and it burns in her gut to think of a small and excitable twenty year old Holtzmann, crushed and in pain because of that woman. And it burns just the same to picture this Holtzmann, thirty-two year old Holtzmann, her Holtzmann, hurting over Gorin or anyone, even as Erin halfheartedly tries to tell herself she deserves it, that she should know how it feels.

But then Holtz answers, "Naaah, not at all. She wanted me to stay. And, ah...she wanted...more from me, when I was there, than what was, uh...happening. Which was nothing." The muscles in her face are strained; she obviously didn't plan enough of a speech. "I kept thinking about what you said, about my toast being a lie. It wasn't. But I could see why you thought so, and that sucked. You all were my family and even though Patty called twice a week and Abby emailed every day and Kevin snapchatted every hour it wasn't the same. I was...homesick." She swallows. "Especially for you."

Erin feels her face warm, and her eyes flit away. "Just because I was the only one freezing you out."

"No. Not just." Somehow, during this last declaration, Holtzmann's ended up directly in front of Erin. Her hands want so badly to be touching her. "I used to believe I was meant to be with Dr. Gorin but as soon as I got there I didn't wanna be. I wanted to be home. I wanted to be back on the roof with you." Holtz releases a crooked, tentative smile. "Not to say the roof is home, though I would live up there with you if that was the only place we could get up to such activities - "

"So what took you so long?" Erin interrupts, because the warm, familiar teasing makes her feel like the sun is her chest and Holtz hasn't earned that yet. She shouldn't be making her feel like that again. "If you didn't want to be there right away, then why did it take almost two months for you to leave?"

Holtzmann's face falls a little, like she's realizing she shouldn't be smiling. "I was embarrassed...and worried you'd hate me. Plus...it felt like leaving would be betraying my twenty year old self. But I shouldn't listen to her...she hadn't even met you yet."

Erin blinks, sending tears coasting along the curve of her cheeks, but she feels herself smiling, too. She recognizes it right away; her Holtz smile. It's been awhile.

Taking the final step across the gap between them, Holtzmann reaches up and thumbs away tears with a tenderness that's somehow surprising; this woman starts fires and triggers explosions, but right now it feels like she's calming some two month long storm that's been raging in Erin's chest.

"I screwed up," Holtzmann says quietly, and this close Erin can really see how terrible she feels about it.

"It's okay. I know the feeling," Erin tells her.

She smiles again, and it feels like relief. "And I solemnly swear, if you somehow ever let me kiss you again, I won't go anywhere after. Literally, we'll set up camp in that spot and never move again if you want."

Erin can't help it; she smiles back. "That's good to know."

At her hip, Holtz's fingers slip between hers and squeeze.

They look at each other, still smiling, eyes alight with almosts and maybes. With promises of soon.

"Welcome home, Holtz."