The task was very easy - all Julia had to do was seize the opportunity when it presented itself. With her mom and dad safely away on some work trip and her brother still asleep, she figured she wasn’t risking much; as long as she brought the device back without any signs of wear and tear, that is, and left it in the same place she had found it. Even if her mom smelled something fishy afterwards or noticed any changes in the settings, Julia could always admit to using it herself. She would probably get scolded for that, but it wasn’t really a thing worth worrying about. In fact, Julia resolved that none of this stuff was worth worrying about… or at least that was what she kept trying to tell herself. Yes, it was an expensive piece of technology and yes, it wasn’t hers to touch and move about, but it’s not like she was a kid that couldn’t be trusted with the simple task of not breaking a commercial device meant to be used by regular members of the public. As she walked to school, all these thoughts raced tirelessly through her mind in a vicious cycle, each of them trying to get an edge over the others but quickly meeting a riposte; like a song that gets stuck in one's head and manifests itself as short melodies that play over and over again; or like recurring flashbacks that have to be reasoned with each time they appear. In an attempt to fight fire with fire, she put on her headphones and selected a playlist with some particularly catchy tunes.

To make space for the device, most of Julia's books had to be taken out of her backpack. She wrapped the machine in a layer of soft blankets to protect it during transit, and as a result could only bring the bare minimum of the things she usually makes use of during the day. She also chose to go by foot instead of taking the bus, complicating her life for the sake of caution, perhaps needlessly. “The girls better be grateful,” she thought, “and not forget to keep their own promises,” whatever those ended up being. She sent her friends a message to let them know what was up.

“You got it?” Martyna asked, having run up to her friend the moment she saw her enter the building.

“Yeah I got it.”

“Can I see?”

“Not right now. On the lunch break.”

“Bummer!”

As the first few classes drew to a close, the ever-tired and every-hungry students began to trickle into the cafeteria; not the fantastic four, though - they headed for the locker room instead, armed with sandwiches and granola bars of their own meant to keep them nourished while the device does its wonders on their nails. Being the hiding spot of choice for teens with acute and very dire privacy needs, it was bound to be occupied by at least one horny pair. Thankfully, no awkward clashes occurred that time as the only duo present in the room, already fully immersed in a session of passionate kissing by the time of the girls’ arrival, got embarrassed by the sudden appearance of an audience and promptly left in search of a less crowded area.

Julia set the package down on a bench and began unwrapping it while the rest of the gang stood around her and observed, waiting for everything to be ready.

“I’m calling dibs, by the way,” Ewa declared, hurriedly.

“What? We were supposed to draw lots,” Zosia complained in response.

“Stop bickering and let me set it up first,” the reluctant mastermind behind this whole beautification venture ordered as she was stuffing the blanket back into her rucksack.

Julia examined the device, checking each of its sides for any signs of damage - dents, scratches, or worse - that could have occurred either during her morning walk or later, at school. Having found nothing of concern, she ran her hand - as if trying to get rid of dust - over the matte, silver surface covering the top of the section that housed the electronics and was equipped with a user interface made up of several knobs and switches, as well as a simple display. It couldn’t have possibly been dirty, though; her gesture was rather a sign of appreciation for the device’s hard work and a humble request that it not bring about any unexpected trouble.

The apparatus in question resembled a modern vinyl record player - one with a transparent lid made of rigid plastic. Most of its volume was taken up by an empty see-through chamber with rubber-sealed openings meant for the hands or feet of the person using its services; they clung tightly to the skin while the machine was in operation, creating an inner environment isolated from the outside world that the robot force required in order to work properly. The floor inside was lined with soft, black plastic, patterned geometrically to improve grip; it had a particular, artificial smell that new things of this kind often have, one that had yet to wither away. The chamber wasn’t very spacious, but it offered enough room to allow for two sets of five nails to be painted at the same time. Directly opposite the opening was the console section; this design necessitated the assistance of an additional person other than the user as it was rather troublesome to operate the device while being confined inside its working station. Besides the interface, it included on its side a square socket, about as deep as an adult’s middle finger is long, and wide enough to allow one to fit inside a few times over. The warnings, as well as the flexible covering which required a bit of force to be moved out of the way, made it clear, however, that the hole wasn’t a good place for fingers or, in fact, anything other than the appropriately shaped, easily insertable robotic modules. Julia wasn’t exactly sure how it all functioned, but she managed to learn to operate it anyway. Located on the side opposite the module holder was a set of sockets of the traditional kind, used mainly for charging the device’s battery; since Julia had already taken care of that at home, there was no need for her to bring along any cables. The machine stood on four sturdy, rubber feet, which - combined with its noticeable weight - ensured that it couldn’t realistically be knocked down by accident.

Julia reached inside a pocket in her backpack and took out the module she chose back at home for this occasion. The elongated silver box was largely featureless, except for its two square sides; the one that faced away from the user while inserted included a window which revealed the contents of the module - a meticulously engineered, though not quite miniscule, robot resembling a model spaceship - while the one that remained visible during operation featured some stickers specifying the technical details. Julia inserted the module into the device like one would load a new magazine into a firearm, and powered the machine up; it began emitting a low hum, oddly similar to those heard when starting up turn-of-the-century PCs, the ones housed in beige-colored cases. While she busied herself with checking the settings, Martyna closely observed her actions, finding the set-up process quite interesting.

“It’s ready, I think,” Julia announced. “Ewa, you can go first.”

“Awesome! So I just put my hands in here, right?” she asked, acting out the gesture in front of her friend.

“Yes, but choose the pattern first,” Julia pointed at the display and started scrolling through the gallery by turning one of the knobs. “I’ve read that you can upload your own designs, but to be honest, I don’t really know how to do that.”

Ewa attentively watched the various patterns go by one by one until a certain image caught her eye.

“Go back, please-- yes, this one. I think it looks great. What do you say?”

“No need to ask me, the only thing that matters is whether you like it or not; but I do think it’s nice. Vintage, fits your style,” Julia assessed. “Should I confirm it? Or do you want to keep browsing?”

“Yes, please! I really like it. I’m worried it would take ages for me to make a decision if I came across another cool pattern, you know?”

“Alrighty!” The girls knew each other long enough for Julia to know exactly what Ewa was talking about. “Feel free to put your hands inside now. Yeah, force it a little. It's meant to be tight like that.”

Everything was ready and the whole gang gathered around to see the magic in person. Julia pressed the button labeled “START” and the device let out a quick, low buzz, giving Ewa - who entrusted its semiconductors and transistors with her hands under the unconscious assumption that no unexpected malfunctions could ever happen - a bit of a freight. There was nothing to worry about, though; as a faint smell of static started to fill the air, the procedure itself began in its usual way. Ewa felt a very soft gust of wind on her fingers and looked at her hands through the transparent walls of the chamber. She saw the pattern she chose appear in succession and row-by-row on each of her fingernails, as if it was printed using some kind of laser. Squinting her eyes, she tried to locate the robots that Julia mentioned but could only spot a vague cloud of blur left behind by something moving extraordinarily fast.

It took the device no more than ten seconds to finish the job - with stellar results. This time, the buzz that sounded to announce the change of active state - the exact same one as before - did not startle Ewa. She asked Julia if it was okay to remove her hands from the chamber; seeing her nod, she did so, gently and cautiously, not wanting to damage in any way her new nail polish.

“Oh my God, it’s so detailed - and there’s so much depth to it,” Ewa said, looking at her fingernails at an angle to better see the spatial complexity of the paint: the peaks, ridges, and valleys meticulously shaped by whatever it was that labored at the speed of light inside the chamber. Zosia and Martyna approached her to see the results and were likewise enamored.

Before the girls had a chance to decide who would be next, however, the doors of the locker room swung open and in rushed a winded boy with a phone in his hand. He took a look around the room and visibly brightened when he spotted Julia, who was observing him with a mix of confusion and frustration.

“Finally! I've been looking for you everywhere. I forgot my charger, can I… borrow…” his speech slowed down as he caught a glimpse of the nail machine. The issue of low battery no longer seemed important.

Unfortunately for Julia, it wasn’t just some random classmate who happened to share the smartphone brand; the boy was her older brother, and he knew nothing - naturally - of his sister’s appropriation of the device.

“Not now…!” she muttered.

“You gotta be joking,” he said with a gesture of resignation. “You brought it to school? Mom is going to be absolutely furious.”

“No, come on! Don’t tell her!”

“That’s messed up, Julia. This shit is not yours.” He started walking towards the girls. “I’m literally going to take it back home right now before you break it.”

“No!” Julia complained and turned towards the device to power it off. She was worried that her brother would pick it up while it was still running and actually damage it. After all, the only thing that he knew about it was that it was expensive; Julia might have borrowed it temporarily without permission, but at least she had some idea how to handle it correctly.

She pressed the power button, and just as she slid out the robotic module, a hand appeared on top of the silver console, as if in an attempt to claim ownership. 

"Oh my God, Wiktor, I'm packing it up. Stop overreacting," Julia said, putting her own hand firmly on the device as well. She crouched without taking it off and deposited the module safely on top of the blanket inside her backpack.

"Absolutely not. I'm not leaving without it," Wiktor was adamant on not letting his sister have her way, lest she would try messing with the machine again later in the day. He grabbed it with both hands and so did Julia.

"Are you seriously going to rip it out of my hands? You're the one who's gonna break it!" she resisted.

"Then just let it go, maybe?" he said and corrected his grip, with one hand now on each of the two sides of the device, both close to Julia's.

"You moron! Don't put your fingers in there!"

With that, a tug of war ensued. The module socket offered some great leverage for those who were bold enough to disregard the safety warnings; it became clear that Julia wouldn't be able to hold on for long. The rest of the girls stood back, not knowing what to do.

And so, amid all that chaos, someone happened to press the power button.