"Okay, so run this by me again. We're getting a what?"

Emma steadied herself against one of the pillars that held up the high, vaulted ceiling of the cafeteria. She was out of breath; she'd stayed after class to chat with the professor, and she'd clearly run all the way here, the better part of a quarter-mile. She was obviously excited about something, but apparently Tammy hadn't been able to make out what she was saying, either.

The three of us had become an informal group in the high-energy metaphysics program, which was why Tammy and I were sitting at the same table, eating our lunches while Emma caught her breath. It wasn't anything special, we'd just ended up as lab partners on an early observation assignment, and it'd kind of stuck. We weren't exactly friends, as far as I could tell, but they were nice enough and easy to work with, which was good enough for me.

"We're-" Emma gasped for air and tried again. "We're...getting...a probability...exciter."

Tammy gave her a blank stare. "And that is...? No, look, sit the hell down and drink something, already. Here." She slid her soda across the table as Emma sat. Around us, crowds of students drifted in and out of the cafeteria, carrying on their own lives, moving with ease and purpose: people who were comfortable where they were and knew where they were going, without even having to think about it.

The wind was still blowing outside; I could see scattered leaves sailing past the windows on the far wall of the cafeteria, which looked out onto the "quad," the long courtyard around which most of the main buildings at Lakeside State College were located. The campus was built on the hillside sloping down into the lake basin, but they'd found a fairly even piece of ground for this, so the concrete walkways running around the central lawn were mostly level. Which was good; soon they'd be getting snow cover and tend to ice up.

We waited while Emma eagerly sipped down half of the drink, gasping less and less as she did. I took a moment to consider the scene. If Tammy was, disability aside, a sculpted beauty, Emma was more of a cute she-nerd. Not the Hollywood "standard vapid pretty person, but with glasses on" look, but the girl-next-door who happened to be an ace at mathematics. She did have glasses, in fact, huge round John Lennon ones, but she wore them well. That she was also heavily freckled, with artfully-tousled hair that wasn't so much red as vividly orange, just completed the look.

And then there was me. I couldn't feel more out-of-place if I had a big label reading "BACKGROUND CHARACTER" superimposed over my face, even though our interactions never felt awkward or like we were only hanging out together out of obligation. And it wasn't like there was anything particularly "wrong" with me by the usual metrics - I wasn't fat or scrawny or short or gangly or ugly or even terribly plain, I just...kinda wasn't there.

Something about going through my life never really having a reason to make the decisions I made just permeated me; I had no presence in my own life. Normally, seeing an attractive young woman (let alone two) spending time with a thoroughly average, boring guy would make people think what is he even doing with her? In my case, I felt, the immediate answer-back would be: Nothing much. Not that I had any specific interest here, but...well, it'd just be nice to think that people would consider it a possibility. Instead, it felt like I just faded into the background, only here because...well, because I was here.

I took a hefty bite out of my cheeseburger, trying to focus on that instead. It was pretty good: the bun just slightly toasted, the tomato reasonably fresh, the cheese made from stuff that had actually come out of a cow at some point, the actual cow ground nice and coarse, grilled just 'til it was cooked through but still juicy inside. The LSC cafeteria wasn't exactly gourmet dining, but it did at least manage "much better than institutional food service," if you were willing to wait for (and, admittedly, pay for) them to actually cook something rather than hustling through the buffet line. Though Tammy's assortment from the sushi bar didn't look too bad either; it helped that they had to keep that stuff chilled.

Once Emma had finally managed to catch her breath, she handed Tammy's glass back to her and took a moment to collect her thoughts. "Okay," she said. "So, neither of you know what a probability exciter is?"

I shook my head; Tammy shrugged. "I'm not up on the really theoretical stuff."

Emma tsk-ed chidingly. Tammy bristled a little, but I didn't mind; I'd gotten enough of a read on her to tell that she was the kind of geek for whom other people not knowing something was an opportunity to share her passions, rather than a chance to lord it over them. Granted, we were in for a lecture either way, but at least it'd be a good-natured one.

"Okay, just a minute," she said, getting up from the table and striding briskly over to the drink bar. A moment later, she came back with a steaming cup of coffee and a couple of those little capsules of liquid creamer.

"Watch this," she said, peeling the foil off the top of one of the capsules.

We both leaned in as she inverted it over the cup, the contents dropping into the hot coffee in one go. As we watched, the half-and-half bloomed up from the bottom of the cup, rising to the surface and spreading out in a pretty pattern before dissipating into the coffee, finally reaching homogeneity.

"Now tell me," Emma continued, "what is it that determines where the cream will flow?"

People telling it what it should be doing, I suppose. The bitter thought flashed across my mind before I stopped myself and took her question seriously. "Convection currents, right?"

"Yep," she said with an enigmatic smile. "But break it down further. What are convection currents? What causes them?"

"Transfer of heat between masses of fluid or gas at different temperatures," Tammy said. "Partly directional, partly random. I think I see where you're going with this."

Emma nodded. "The major currents you saw were fairly consistent, of course - the cream rises in the coffee as it warms, then settles as the temperature equalizes. But you also saw all the little curlicues as it bloomed out."

I nodded. "Those are more random - Brownian motion, right?"

She smiled. "Correct! Of course, at that level, it's more apparently than truly random - if you could track the motions of the molecules individually, you'd see all the little micro-interactions that cause the motions we observe on the macro level. But there's a probabilistic element to everything, if you drill down far enough."

"We're gonna start talking about cats in boxes pretty quick here, aren't we?" Tammy said dryly.

Emma chuckled. "If you want a different metaphor for unpredictable actors that are only in a known state when observed, we could always use your roommates."

That got a laugh. "The Little Divas? God, tell me about it."

"So let's imagine it like this," she continued. "If you have one unpredictable actor in a box, you don't know what they're doing until you open the box, but there's only so many possibilities. There's a finite probability of any given thing happening, even if nothing is in a fixed state until you open the box. But if you have a thousand unpredictable actors in the box, all interacting with each other, and each interaction is its own probabilistic event? Well, God knows what all might be going on in there, until you open it."

"That...would explain a lot, frankly," Tammy mused, as someone off in another corner of the cafeteria started a loud argument about a rival sports team from the local Catholic college. "It's been like the freakin' Hangover movies every Saturday morning since the start of the school year. And that's with just the two of them."

"Right. Now let's imagine that you have a mechanism that can admit actors to the box without opening it, and then open it at a certain specific time. Given that, you could view the box as a means for storing what you might call 'probability potential.' You could use such a mechanism to charge the box to a certain level of potential, and then release it."

"And that's what a probability exciter is?" Tammy said. "Okay, interesting idea, but what do you do with it?"

"Well, that's the question," Emma said with a shrug. "It's still extremely new technology - they've only just started building the things in the last couple years, and most of the initial experiments have been the probabilistic equivalent of smashing particles together to see what they break apart into. But the potential is highly interesting, especially for metamorphic research."

I finished the last bite of my burger as I thought about what she was saying. "It's a means of making things more predictable and repeatable, isn't it?"

She grinned. "Exactly! That's been the whole problem thus far - the best we've gotten for experimental methodology is variations on 'expose subjects to slightly different high-energy fields and see what happens.' But if we can actually induce events at a specific level of probability, we can start to make meaningful determinations about the potential for inducing controlled transformations. This could be a leap forward for metamorphic research like nothing we've seen before."

Tammy raised an eyebrow. "As in, if you could work out the probability of a specific change, you could make it happen reliably?"

"Potentially. It's going to take a lot of research before we could work that kind of thing out ahead of time, though. For starters, it's going to be more inducing changes at specific probabilities and seeing if the results are consistent from subject to subject."

"Huh. Damn." Her disappointment was audible. What had she been hoping to hear? I thought to myself. It'd be natural to be disappointed when an apparent quick-'n-easy shortcut to your goal turned out not to be, but she hadn't even known anything like a probability exciter existed fifteen minutes ago. I wondered exactly what Tammy was willing to go through to fix her legs; what changes would she willingly risk? But I wasn't about to ask; at least she had a goal, which was more than I could say for myself.

Emma smiled sympathetically. "Scientific progress rarely comes as easily as we like. But it is a very promising technology; I'm sure that we'll start seeing some practical applications for it within the next five or ten years."

Tammy looked about as thrilled with that as one might expect. I figured that it would be good to redirect the conversation at least slightly. "So do they have any specific plans for the one we're getting?"

Emma shrugged. "Dunno; I only just found out about it today. I know Dr. Holland has written papers on the potential for therapeutic transformation, so I'm sure the department is going to be doing some work in that vein, but I don't know who's planning what or when." She sighed. "I mean, I'd love to have a crack at it myself, but I don't expect they're going to let the freshies play with a multi-million-dollar piece of high-powered bleeding-edge lab equipment."

"Yeah, s'pose not," I said. "Still, you could at least get to watch some pretty cool experiments, right?"

"Well, yeah, but...you know how it is. It's different getting to do what you want to do, even if it is basically the same thing."

Might be if I did want to do it, I thought. Well, it wasn't like it wasn't interesting, in the abstract, but I couldn't pretend to have anything like that kind of passion for it. "Maybe you'll get lucky," I said. "Most of the faculty in our department seem pretty decent. They might at least let you assist or something; I hear Dr. Curtis is pretty chill about student involvement."

She brightened a little. "Yeah, maybe. Hopefully by the time my grad project rolls around we'll have a chance to really put it to use." Then a dry chuckle. "But the only thing Curtis wants assistance with during the fall semester is lining up tickets for college hockey. I'm not sure what that guy is even doing in the sciences."

Tammy laughed. "Hey, he's pretty alright, other than the clown hair. And he does do actual research work. You know, when it's not hockey season."

I chuckled and nodded. "Well, maybe one of the other faculty, then. Gives you some time to think about what you'd want to do with it, at least." I wondered what she would do, given the chance. I thought about asking her, but the alarm on my phone beeped and I realized I was supposed to be getting over to one of my math classes. I said a quick goodbye and left Tammy and Emma to finish up lunch themselves.