"Come here often?"

Erin whipped her head around at the low, husky female voice behind her. There, slouched in a chair with her boots on the table and a lit blowtorch in her hand, was a woman. She was dressed in stained overalls and she was wearing not one but two pairs of yellow goggles—one on her face and a larger set nestled in the wild mess of blonde hair protruding from her head.

At the time, Erin didn't know that those three words would irreversibly alter her life. If she had known in that moment, she would've picked up her briefcase and left. Erin Gilbert, doctor of particle physics, was this close to having the life she had always dreamt of. She was being reviewed for tenure at a prestigious university. She wasn't married yet, but she had a steady boyfriend of nearly six months. She had a good relationship with her parents for the first time in a long time. Things were finally how they were supposed to be, and she wasn't about to let anyone or anything veer her off course.

Not ghosts. Not Abby Yates. And not this woman, whoever she was.

Erin hadn't thought about ghosts in a very long time. They were locked away in a tiny part of her brain along with all thoughts of Abby and their book. She wasn't allowed to think about those things.

Until she was forced to, because Abby had started selling the book without Erin's permission, and now Erin was standing in the musty basement of this sad excuse for a college, and the woman who used to be her best friend was now more interested in yelling about soup than talking to Erin. As she had stormed off, barking into her phone, Erin had set her briefcase down, fully intending to wait until Abby came back so they could have a mature conversation about all this.

And then—the blonde woman. Come here often? She was still gazing at Erin expectantly.

"I'm sorry, hello?" Erin cocked her head to the side. "Who are—who are you?" she stuttered, caught off guard by both the pick-up line and the fact that there had been someone else in the room to witness her conversation with Abby.

The woman swung her feet down, her boots hitting the floor with a solid thunk, and tossed the blowtorch onto the table as she stood. She pulled her green protective gloves off as she slunk towards Erin, revealing fingerless brown leather gloves beneath them. Did this woman wear everything in multiples?

She extended her hand to shake Erin's with a cocky smirk on her face. "Holtzmann," she said.

A strange name—a last name, Erin supposed—but it suited her. She was even more bizarre-looking close up. Erin's eyes flickered down to the large silver pendant hanging around her neck from a thick chain: a letter U with a screw spiked behind it. Erin got the joke instantly, and her mouth twitched into a bit of a smile as she returned Holtzmann's shake. "Erin."

Holtzmann's smirk turned into a full grin. "I've heard terrible things about you."

Erin's heart sunk a little. All her life, people had formed judgements about her without ever speaking to her. She'd always had a desperate need for others' approval, and she'd finally hit a point in her life where she felt like she had more control over people's first impressions of her. The fact that this woman already had God knows how long of Abby chirping bad things in her ear didn't seem like a good start. Erin tried to remind herself that she'd probably never see this Holtzmann again, but instead of soothing her spirits, the thought made her kind of…disappointed.

Abby had returned. "Holtzmann works with me here in the lab. She's a brilliant engineer." An engineer? She didn't look like an engineer. She looked like…well, Erin wasn't sure what she looked like. A mad scientist, maybe?

Holtzmann slung her arm around Abby's shoulder, and Erin felt a little pang of jealousy run through her. How long had they been working together? Had Holtzmann been…her replacement?

"And," Abby continued, "very loyal. She would not abandon you."

"I get it," Erin said snippily.

"She also happens to specialize in experimental particle physics."

That caught Erin's attention. She tried to keep indifference in her voice as she said, "Oh."

Holtzmann had removed the yellow glasses from her face, and with the obstruction gone, Erin was struck by how beautiful she was. Her eyes were the most brilliant shade of blue. Erin's stomach dipped a little. Pretty and smart? Hold on—she had a boyfriend. What was she doing?

"Holtzmann and I are really busy here actualizing what we just theorized about in our book."

Holtzmann was staring at Erin. She was blinking with an infrequency that was a little unsettling. Erin felt exposed, somehow, like she was naked.

"Really?" Erin asked, squirming a little.

"Yeah. We're incredibly close on the hollow laser for the reverse tractor beam. Really close."

"You're making a reverse tractor beam?" Erin couldn't help herself from being intrigued. As much as she didn't want to engage with any of this nonsense, particle physics excited her.

That's what made her go listen to the supposed EVP. That and because the little eight-year-old inside of her still wanted to be proved right even after all these years.

And it was a joke.

As they laughed and made fun of her, she decided she'd had enough. She'd find another way to get the book taken down. Maybe she could contact Amazon and tell them that Abby was violating copyright, or something. She was done with this.

She should've just walked away without engaging in any more conversation. She shouldn't have mentioned Ed Mulgrave. She didn't think they would actually take it seriously. She watched in disbelief as they sprung into action. Holtzmann strode across the room, stripping off her lab coat to reveal an olive green crop top under her overalls. Erin got temporarily distracted by the bare skin on her sides.

"Wait, you're going?"

"I got the pack," Holtzmann said, bending to grab a silver bag and a jacket.

Erin felt strangely hurt that Abby hadn't actually been inviting her to join them. She shut the door to the lab behind her and chased after them, calling Abby's name. Holtzmann, now clad in a black leather jacket, ran like she didn't know how humans were supposed to run. It was kind of…endearing.

"Come on," Erin said when she caught up to them, "please Abby, just take the book down. Please."

Holtzmann was leaning against the side of the cab with her jaw jutted out, making faces at Erin as she negotiated with Abby. It was very distracting.

The three of them piled into the cab to head to the Aldridge Mansion. Erin's motivations were still to get the book taken down, but she was…a little curious, too. She listened to the pair's excited banter from the back seat. A finger prodded her shoulder.

"Hey," Holtzmann said, "Dr. Tenure. Did this guy mention anything more about the ghost when you spoke to him?"

Erin twisted in her seat and shook her head. "Just said the building was haunted. And don't call me that. You can call me Dr. Gilbert or Erin." She'd had more than enough of her share of nicknames in the past.

Holtzmann smirked. "Roger that, Dr. Erin." She gave Erin a two-fingered salute and resumed her conversation with Abby.

Erin sighed and turned back to face the front. She was beginning to get the sense that Holtzmann took nothing seriously.

After they arrived and she made the introductions, she could've just left. She'd held up on her side of the bargain. Her curiosity led her inside, though, to where Abby and Holtzmann were setting up their equipment.

As Abby walked around with her PKE meter, Erin became aware that Holtzmann had her video camera pointed right at Erin. She swatted it away, but Holtzmann brought it right back. She knew the strange engineer was probably only doing it to bug her, but she felt a little flattered none-the-less.

"Ma'am, can you tell us where you got the world's tiniest bow tie?"

"Uh. It came with the shirt?"

"Can you tell us what it's like to walk around in those shoes all day?"

A little thrill went through Erin at the thought of Holtzmann checking out her outfit, even if it was only to make fun of her. She was a little disappointed when on her next time swatting away the camera, Holtzmann walked away instead of persisting.

The disappointment was short lived, because soon she had a much bigger problem on her hands. She watched the eerie blue light flooding out of the open basement door, completely spellbound. A loud crunch made her flinch. A glance down the line revealed that the source of the noise was Holtzmann…eating Pringles.

"How can you be eating right now?" Erin said through clenched teeth.

"You try saying no to these salty parabolas."

That—what? Who was this woman?

Then…the ghost. Rounding the corner, dress swirling in tendrils around her ankles, glowing blue.

"This can't be happening," Erin said.

"Oh, it's happening all right," Holtzmann said. Her voice was distinctly calm. Firm, but anchoring, somehow. Erin felt a pang go through her, and despite having known the woman for less than an hour, she found herself wishing that Holtzmann had been there when she was younger to reassure her that what she was seeing was real.

She had to talk to it. She just had to.

The slime was so unexpectedly horrible. As it showered down on her, soaking every inch of her suit and hair and skin, she heard the distinct crunch of Holtzmann eating another chip.

Then it was over, and the ghost was flying through the window, and they were spilling out onto the street, and all Erin could do was shout 'We saw a ghost,' over and over and over while Holtzmann danced around her.

They stayed out there for twenty minutes, coming down from the high. Holtzmann swiped a finger along Erin's cheek to pick up some of the slime and tasted it 'for science.' It…kind of turned Erin on. Wait, what? The strip of skin that Holtzmann had touched tingled for a while afterwards.

Abby and Holtzmann said they were going to go out for drinks to celebrate, and they invited Erin along. Her eyes flickered back and forth between them: Abby, whose eyes were starting to sparkle with something that may have been forgiveness, and Holtzmann, whose own eyes were filled with a kind of manic glee. Erin wanted to say yes. She wanted to celebrate not being crazy, and catch up with Abby, and learn more about the fascinating woman beside her.

Instead, though, she declined with the excuse that she needed to shower. And she had class to teach the next day. Was it her imagination, or did Holtzmann's face fall when she said no? Quickly, she asked if she could come back to their lab the next day after she was done work, so they could discuss what just happened to them. She wasn't ready to say goodbye to either of them. Holtzmann said yes without a hesitation.

Erin bade them farewell, and headed for home. Later, after an excruciatingly long shower trying to remove the surprisingly invasive slime that clung to her body, she curled up in bed and thought about how much her life had just been changed in a day. In the span of a few hours, she had seen a ghost, reconnected with the greatest friend she'd ever had, and met…the strangest human she'd ever encountered.

Oddly, it wasn't the ghost that kept returning to her head. It was a nuclear engineer she barely knew: a puff of blonde hair, odd yellow glasses, and the way that she had kept so calm while they stood face-to-face with a ghost. Erin didn't know what to make of her. She didn't understand her.

But God, did she want to.