Life has a forward momentum and even being aware of its inevitable ends doesn't slow it down for long. While they didn't really have a big ceremony, Erin and Holtzmann eventually made their commitment official in the eyes of their friends and the New York government. It didn't change much about their daily lives, as they had already moved in together a couple years before, but it was nice to make the gesture. And although Holtz didn't have any other family who could try to supersede Erin or their friends on issues of inheritance or medical visitation rights, it made both of them feel a little better to have it all on paper.

While they were building their relationship, Patty found a wonderful man who adored her and inherited two stepkids who quickly became beloved parts of the whole Ghostbusters family. Holtzmann immediately claimed the Crazy Aunt title and let the kids get away with everything behind Patty's back.

Abby never opted to marry, more interested in the work than having to balance it with the demands of a relationship, but she never had a shortage of suitors when she wanted some entertainment, especially given their status in both the scientific community and the public eye these days. Erin took great pleasure in watching her hold court at physics conferences, getting to pick and choose who she would give a quote to or accept drinks and a conversation with, after so many years of being the laughingstock of their profession.

Their small operation expanded over the decades, adding satellite branches across the country, then around the world. The firehouse remained the hub and business center for the whole thing, packing more and more lab equipment into any space not being used for offices or meeting with clients. Although they hired and trained up enough new recruits that they didn't have to be on call 24/7, the original team still ran the vast majority of busts together, letting the new teams build their own dynamics and rhythms. Things were busier, but for the most part, the good bits of the job hadn't changed. They built equipment, elucidated new concepts in mankind's understanding of the universe, busted ghosts, hung out, danced, and generally enjoyed their lives and work.

Things were going so smoothly, Erin almost forgot the genetic elephant in the room, but it never completely left her mind. In her spare time, when the others weren't around, she researched everything she could find about Holtzmann's disorder, sparse as it was, as well as advice and support forums for families living with relatives with Huntington's, Alzheimer's, dementia, and every other neurological situation she could think of. She may not be able to stop it, but she could be ready to give Holtz the best support possible when the time came.

All told, they got relatively lucky. Holtzmann was forty-six before the tremors started showing up in her hands, and then only after long work days or hours of precise, strenuous building. She was forty-nine before they got bad enough that she didn't trust herself to work on their equipment anymore. By then, the original team had mostly stepped back to more of a support and research role anyway, but it was a hard moment for Holtz, accepting that she had to give up such a central part of who she was.

In truth, all the girls decided to officially retire at that point. Holtzmann protested that no one else should have to stop because of her, but honestly the rest of them were pretty much all ready to leave the field work to the younger kids. Erin was nearing her sixtieth birthday, Abby had already had hers, and Patty was looking unfairly younger than any of them despite being sixty-five and a grandmother.

They contacted the mayor's office to discuss their decision and were given an appointment for that same week. Mayor Lynch, despite being well into her campaign for senator, still tended to make time to meet with the team directly rather than foisting them off on one of her staff. Though, to be honest, that was more likely out of desire to limit how many people they talked to than in deference to all they did for the city.

Lynch wasn't surprised by their decision to retire in itself, but Erin caught the startled break in her politician's façade when they disclosed Holtzmann's condition to her. She agreed to have an aide start their paperwork for pensions and transfer their organization's leadership to the new senior team of their choice, as well as draft a press release to handle the changeover while encouraging discretion as to the details of their reasoning. She also insisted there would be a retirement ceremony so that the city could express their gratitude, no doubt while also providing her with ample publicity opportunities to add to her campaign's press coverage, but promised the team themselves wouldn't have to do much aside from put in an appearance and enjoy a meal and drinks.

As they were heading out, Lynch called, "Dr. Gilbert, could I have a word? Just with you?"

Erin exchanged a puzzled look with the others, but touched Holtz's shoulder reassuringly and said she would meet them at the car.

Once they had gone, Lynch dismissed her assistants as well and they were left in the awkward tension that always characterized their interactions.

Lynch steepled her hands in front of her with a solemn air. "Holtzmann. This isn't a joke, is it? Because while I wouldn't put it past her—"

"No," Erin said, feeling emotion make her voice rough. "She's not making it up. We can give you the medical reports to prove it—"

"No, that won't be necessary." Lynch exhaled slowly. "I'm genuinely sorry, Erin."

That shook Erin a bit. In all the years they had worked together, Lynch had almost never used their first names. "Thank you."

"I'll let you get back to the others," she said, straightening and reaching for a folder on her desk, "but I'm aware that chronic medical care can be very expensive, especially for rare conditions that may need elaborate experimental treatments. If there's ever a concern about getting something done, let me know. Funding can always be found."

Erin blinked, nearly speechless. "Uh, thank you, Mayor Lynch. Jennifer."

She sputtered some further farewell on her way out. Looking back one last time, she saw Lynch set down the folder, remove her glasses, and run a hand over her face. She stayed like that, staring into space for a moment more, her expression hard to read, before taking a breath, putting her glasses back on, and getting back to work.

As Erin took the elevator down, she pondered the odd relationship that had formed between the team and their reluctant government liaison over the years, and felt a new pang of emotion over the era of their lives that was ending.

OOO

After the hoopla and attention—being careful not to draw public attention to Holtz's situation—had died down, retired life settled into a pretty comfortable routine. Patty focused more of her energy on her writing, adding more books to her already impressive bibliography about the haunted history their work uncovered and enjoying the speaking tours she got invited to do. Sometimes Abby joined her, but she mostly preferred staying involved in the research end of things, keeping a toe in Ghostbusters business even as she embraced her emeritus status. Erin and Holtzmann devoted their time to each other and to researching everything available on gene therapy and biotechnology.

Despite her initial depression when the symptoms kicked in and took away her ability to work on her babies, Holtz's readiness to fight the disorder's onset came back as she and Erin took on the problem as a team.

"No one with this syndrome has lived past sixty," she said, pacing in front of the whiteboard in their living room like a coach before the big game. "Yet. So a minimum of sixty-one is the goal."

"Well, many happy years into the future is the goal, but basically, yeah," Erin said, waving a hand.

Holtz strolled back to stand beside Erin, both folding their arms in sync as they stared at the thought-web of medical research on the board that once held quantum physics theory. "So the next step is…"

"Just figuring out how to get there…" Erin finished.

"I was going to say deciding what to order for dinner, but that too."

They attacked the quest for a cure with a motivation Erin hadn't felt since high school. Although this time it was perhaps even stronger because instead of just proving the existence of ghosts (and her sanity), now she was trying to save Holtzmann's life. They chased leads from medical journal to medical journal. They travelled to neurological research facilities around the country and even to a few other countries, consulting with experts. They had a long Skype conversation with a very confused specialist from Ecuador before Patty finally made Erin move over and finished the call in much more fluent Spanish. Erin and Abby even got Holtzmann some simplified lab equipment so she could run a few tests on her own or simply distract herself when the frustration was getting to be too much. They read and watched and compared everything documented on the subject until Erin was dreaming in words like 'prion' and 'glia' and 'myelin'.

And then one day they found out an experimental trial was being started at a university hospital to treat a suite of related conditions including Holtzmann's. They contacted the program in excitement and began filling out an application and patient profile through Holtz's primary specialist, excitement flooding their veins at the new options opening before them.

And it absolutely devastated Erin when Holtzmann got rejected. Apparently the combination of her age, stage of progression, and lifetime exposure to ionizing radiation made her a non-ideal candidate for their research.

Abby and Patty were likewise livid. Abby was ready to go over to the medical center, no matter what state it was in, and demand who they were to think Holtzmann was unqualified for anything. Erin was already pulling up Lynch's number, figuring some senatorial pressure might grease the wheels a bit.

Out of all of them, Holtzmann was the only one not visibly upset. She had watched them rant from her seat on the couch ever since they opened the e-mail, but now spoke up, her calm voice managing to catch Erin's attention through the anger.

"Erin, put the phone down."

"We can do it, Holtz. After everything you've done to save the world, Lynch owes you."

"Er," she soothed, reaching out a hand to entice Erin back over. "You're thinking with love, not science. And while I adore that, I need all sides of your brilliant brain onboard. It's gonna be fine. They don't need my mutant DNA contaminating their data and slowing them down. I mean, they're doing the study whether I'm in it or not, right?"

Erin wanted to protest, glancing toward Abby for support, but knew it was moot."That's true," she admitted reluctantly, letting her righteous anger fade a bit as she moved back to take Holtz's hand.

"So all we've gotta do is wait until they figure out a fix. Only difference is I don't have to spend the next few years as a guinea pig, much as I love my communal rodents."

Erin sighed, looking down at Holtzmann. Over the last two years, her tremors had worsened to involuntary spasm-like movements as her nerves triggered randomly. She rocked compulsively when she sat, sitting still now an impossibility instead of just a difficult request. People could tell more that something was off about her, rather than just her inherent quirky behaviors they had come to expect. But she was still able to do most things on her own, if slowly, and in every way that mattered, she was still herself. Erin was grateful for that.

"You're right," she said, squeezing Holtz's hand firmly. "It's just…I want to do everything I can for you."

"You have. You are." Holtz pulled her closer, smirking. "And right now, that means keeping me busy so I don't hassle those s for updates every day."

"I think we're gonna have to keep both of you from doing that," Patty snorted.

Erin gave Holtzmann a coy smile. "Well, if that's what you need, I'm sure I can find ways to distract you."

"Yeah, you can," Holtz grinned, drawing her down for a kiss.

Erin heard Abby and Patty groan nearby and affectionately flipped them the finger.

As they separated, Holtz pushed back, face somber. "Hey, all seriousness though, I need you guys to promise me something."

"Of course," Erin replied, the others echoing her response.

"If we can't find a cure for this, I don't want anybody blaming themselves. I accepted this a long time ago, and I want to get at least ten more years in to beat the record, but if anything happens, that's just the way it is, okay? No guilt to go around."

Erin's heart clenched thinking about that outcome, knowing if that came to pass, no matter what she said now, she would always wish she could have done something more. But still, she nodded and patted Holtz's hand between hers. "I promise."

Holtz extracted her hand from Erin's and held it up, making an effort to clench all her fingers except the smallest one. "Pinkie swear."

Erin laughed now, catching the shaky finger with her own. "Pinkie swear."

"Come on, all of you," Holtz said, turning to Abby and Patty with both pinkies raised.

They shook on it too, the grim feeling in the room effectively broken.

"Okay, now spit in your palms," Holtz ordered.

"Uh-uh. Baby, we already swore on it," Patty said. "I'm not doing a spit shake too."

"Spit shake?" Holtz asked, puzzled, reaching for one of her probes. "I just have a conductivity experiment I want to try."

As Erin dissuaded her from using them as test subjects, she sent a wish of good luck to the researchers doing the trial.

OOO

The rest of the year passed slowly. With the knowledge that it could be years before the trial showed any practical results and every other lead already exhausted, distractions were harder to come by. At Patty and Abby's insistence, the couple finally took some time in their retirement to just be together, no ghosts, no research, just them.

They made a list of goals to accomplish while Holtzmann still had the health and mobility to do them, including a trip to the Marie Curie Museum in Poland, a concert in Vegas Erin had long had on her bucket list, a visit to Legoland that was on Holtz's and an actual lay-on-the-beach-sipping-fruity-drinks vacation far from anyone who knew them. Against all odds, an actual retirement.

Over the years, Erin was getting used to seeing the physical changes in Holtzmann. She knew she had her own share of changes, bitterly embracing the wrinkles and graying hair since Holtz swore they were just charming new aspects to her beauty. Being ten years younger, Holtz wasn't quite as far along that progression yet, but the neuromuscular symptoms of her disorder made her move like she was the older of the two. It still hurt both of them when she realized she couldn't do something she used to, but between them they could usually figure out an alternative or rig up a technological solution to help her retain some independence. And if she needed to walk slower than they once had, well, Erin certainly didn't mind taking their time instead of rushing to their destinations. Besides, her dancing had never relied on fluid, controlled movements anyway.

Erin could gauge the physical progression of Holtz's condition pretty clearly, and had prepared herself for it. The difficulty with motor control had set in slowly, and so she had gotten time to get used to that as their new normal, although she was sure it was still more difficult for Holtzmann to accept, no matter how much she kept her spirits up. Hearing about the internal effects was harder. Erin had tried not to cry the first time the doctors had started prescribing medications because several of Holtzmann's organs were showing reduced function. But as long as she kept up with her scheduled meds, which Erin made certain of, that at least seemed to be under control. She just took comfort that research on a cure was in the works and this would hopefully be a temporary situation.

Holtz's mental condition was much harder to get a sense of. To be fair, her baseline mental behaviors were a bit hard to predict even in her youth. Add on top of that the fact that all four of the teammates were postmenopausal now and forgetting what you were doing, misunderstanding each other, and feeling scatterbrained were relatively frequent occurrences for any of them. So it was hard to pinpoint exactly when the trouble really started to set in. But Erin knew exactly the moment it became real for them.

She had walked into the bedroom one afternoon to find Holtz sitting on the side of the bed, head resting on her closed fists, which she was tapping against her forehead, muttering to herself, agitated.

"Holtz," she said, cautious, but hurrying to her side. "Honey? What's wrong?"

Holtzmann looked up at her, eyes filled with desperate fear. "Er. What's our receptionist's name?"

That threw her. She tried to remember who was working at the firehouse these days. "Uh, the new girl? Allison, I think—"

But Holtz was shaking her head violently, eyes squeezed shut. "No. Our receptionist. Big guy, forty-watt brain, but built like a god…"

A trickle of ice water slid down Erin's back. "You mean Kevin?"

"Kevin!" Holtz exalted. But instead of relief, she started bumping one fist against her forehead in rhythm as she repeated "Kevin, Kevin, Kevin", as if forcing his name back into her mind.

Trying to keep her fear from showing, Erin gently caught Holtz's fist, covering it with her hands to keep her from hurting herself. "That's just a momentary lapse," she ventured. "Happens to everybody. I've called Abby 'Patty' before."

"I've been trying to remember that for three days," Holtz said, voice dull and defeated. "I saw him and couldn't remember it."

Erin rubbed her arm reassuringly. "We're all getting older, Holtz. These things happen."

"I can't remember pi beyond ten places anymore," Holtzmann said flatly. "I have to look up blueprints to remember how our proton packs worked. I don't remember what city I was born in or what college I did my undergrad at." She wiped her free hand across her eyes. "I could deal with that, all of it. But this is the first time I forgot something big about one of you guys."

Her face crumbled as tears started to roll down her cheek, her breath escalating with panic. "It's trying to take you guys!"

"No." Erin pulled Holtz against her, wrapping her tight in her arms as if she could shield her from the disorder. "It can mess up some of your memories, but it'll never take us. We're still here. I'm still here."

"I don't want to think you're a stranger someday," Holtz sobbed against her chest.

Tears burned Erin's eyes as her heart clenched. That fear had haunted her mind too. "We won't let that happen. If you lose any memories about us, we'll just make new ones to replace them, okay? We'll just keep making new ones so you never run out."

Holtz nodded, but continued clinging to her, not fully comforted. Not that anything could make the reality easier or less inevitable.

Erin kissed the top of her head, hating that some of those brilliant, intricate neurons could be flickering and dying even now, and there was nothing she could do to stop it.

As she held Holtz and stroked her hair, she just hoped the research trial would come up with something soon.