A crucial thing that set Tesla apart from the rest of the Arrancars was that he still had his heart.

Don't think of this the wrong way, though. All Arrancars need some semblance of a heart to power the blood so many of them desire to spill. But Tesla was different – he lacked any sort of Hollow hole, and so, theoretical or physical or something else entirely, the whole of his heart still was quite alive somewhere inside him. I never suspected this from the beginning, since unlike a majority of other Arrancars (especially the females) his uniform concealed his entire form below his jaw. Only the gap at his elbows between the sleeves of his coat and his black gloves was visible.

This wasn't enough for anyone to reason that Tesla was anything extraordinary. For the most part, everyone other than his higher-up Nnoitora left him alone simply because he was Nnoitora's only Fracción. Nnoitora was notorious for being cruel and volatile, so it was unwise for even the strongest of Espada to anger him if they wanted to avoid a fight. If it weren't for that time I came across Tesla, I would have been able to adhere to this rule just as well as anyone else in Las Noches.

It was one of those days when something important was going on in the Living World or something, and at least a few of the Espada were out on some sort of mission of which I was unaware. As a result, Las Noches was much more empty than it would be most other times. This piqued my interest, and I was spurred to wander aimlessly about the giant building just to see what it would look like with so few Arrancars in it.

I probably would have guessed that Nnoitora was in a foul mood because he wasn't invited. He was generally very irritable, and that may have been one of the reasons he was left behind. It was for this reason that when I crossed paths with him somewhere inside Las Noches, as I knew I inevitably would, I put effort into avoiding eye contact.

The lanky Espada passed by in a narrow hallway without much incident, for just his ominous presence was enough to make me shudder and I had no trouble keeping my gaze away from his. But out of relief I raised my eyes immediately as he passed and so I caught my unintentional initial glimpse of his sole Fracción.

Tesla was telling Nnoitora something as he approached me. I don't recall his words, but I remember watching him hurry after his higher-up and listening to his urgent voice. It sounded husky but quiet, and depressingly enough, as though he was constantly trying not to cry.

As he rushed past in the narrow passageway, Tesla brushed my side and I stumbled against a wall. I didn't consider the matter very important myself, but Tesla apparently did. I didn't remove my eyes once as he paused for a moment to apologize. In that second or two I got a decent look at his face: the last of his mask was across his forehead; there was an out-of-place-looking green stripe on the right side beneath his eye; his eyes themselves were a dark, deep gray, and they reflected a fleeting glimpse of loneliness from somewhere deeper within. I barely heard anything he spoke before he turned and continued after Nnoitora. Watching Tesla's lithe form disappear down the hall and listening to his voice in my mind, I barely stopped myself from calling him back. Though I had only been anywhere near Tesla for a few seconds at most, in that short time I was already beginning to wish that he didn't seem so… alone.

Only when his presence faded completely from my senses did I turn back in the other direction. A nameless force was tugging at my mind, making me want to already see him again. Nevertheless, Tesla had gone somewhere else, and I didn't expect to encounter him once more anytime soon.

That was both the first and the last time I ever saw Tesla with both of his eyes intact.

The next time I saw him at all was quite a while later. At this point I had completely forgotten about the hallway incident, but I was about to remember it before I could protest. I don't remember why I was outside the building anymore, though now I'm not sure it matters. I recall that I had rounded a corner when I spotted them: two unfamiliar small Arrancars, both female, and who appeared to be sisters. They were facing away from me, towards the more pressing matter; Nnoitora was standing over them, watching them cower with what could have easily been as much of a scowl as a smile on his face. The two Arrancars were clearly terrified, and I could hear their whimpers from where I stood. Needless to say, I couldn't stop from interrupting.

"What are you doing?" I questioned loudly, slowly advancing towards Nnoitora. Somehow I had forgotten how scary he was (at least for now). "Back off from them."

Nnoitora's narrow eyes lifted towards me, halting my progress abruptly. "Don't interfere," he snarled. With a swift glance over his shoulder, he barked out one word: "Tesla!"

This was the first I learned of the Arrancar's name, and so I had no time to react before I heard the unforgettable voice: "Yes, master."

The memory of the encounter in the hallway rushed back to my mind in the moment it took Tesla to carry out his silent orders. In an instant he was behind me, although by the time I had registered that he had already struck me in the back. A sharp pain blossomed from my spine as something constricted my front, and from that point I couldn't move an inch – only watch as Nnoitora continued towering over the petrified duo of Arrancars.

In half a second I was aware that Tesla was the one restricting my mobility, catching me between one arm and the rest of his body. For another half of a second I was simply standing there wondering what to do, but after that my senses returned, and I noticed something strange – Tesla was warm. I had never gotten close enough to another Arrancar to know for sure what their body temperature was, but I was positive no other Arrancar could be this warm. Maybe it was just because he had his arm around my front and was holding me against his own body to keep me in place. It was almost like he was … alive.

I was too distracted to watch Nnoitora anymore. Having so much contact with Tesla, let alone anybody else, was entirely new to me, and I was starting to panic. I was definitely not used to being able to feel his form against my own. Unnerved, I tried to free myself, but his grip was too strong.

"Stop being difficult," he hissed, stopping my movement instantly. His voice was soft enough at a distance, as I remembered from before, but almost directly against my ear was enough to halt any sort of anxiety I could sense. I thought this strange, since if I was a prisoner witnessing a cruel Espada entertain himself I should just be trying even harder to escape. Despite them being a command, Tesla's unnaturally quiet words calmed me, and somehow I relaxed against him.

That was my mistake. Perhaps if I hadn't let myself rest so easily, I never would have found out Tesla's secret. But when I allowed myself to repose against his front, I felt it: a vague pounding sensation against my shoulder that was so faint I wondered at first whether I had imagined it. Nevertheless, a moment passed, and the sensation continued. Initially I was worried that I had some sort of iron deficiency and thus a bad twitch – then I realized that the thrumming was coming from outside me…and inside Tesla.

My breath practically caught in my throat, and if I wasn't careful Tesla's grip could have choked me right there in that strange embrace. For longer than I could remember I had never once thought about such a thing, and now an odd, long-forgotten memory was returning: the memory of a heart.

I turned my chin upwards slightly to meet Tesla's gaze, but in an instant that had become one of the most difficult things to do; while one gray eye, his left one, kept as vigilant a watch on me as a wolf on a deer, the other one was concealed behind a patch, and the remaining signs of a recent gash still rent that side of his face around its borders. I was forced to drop my eyes instantly before I could find my voice again.

"You… your name is Tesla, right?" I asked slowly.

"It is," he replied without hesitation. I started to think I shouldn't have asked such a dumb thing; his voice was in my ear again, prompting me to relax against him once more.

You're being an idiot, I told myself, closing my eyes to block out the images around me. I heard the two Arrancars dodge and begin to flee form Nnoitora before I lost track of their location.

The next thing I knew was that I was cold. My eyes snapped back open and I took in my surroundings. How did I get on the ground? I had either fallen or been dropped, because my hip stung and I guessed that it was bleeding. The two Arrancars were nowhere to be seen, and Nnoitora seemed to have vanished as well. What had been going on before, again? I was watching Nnoitora, and Tesla was…

Had I fallen asleep? I vaguely remembered shutting out my sight – that may have been part of the cause. The other part was…

I hastily stood up. Tesla's back was retreating a long the wall, headed for the entrance I had left through earlier. Suddenly I didn't want him to leave – his presence so close to my own had been oddly placid, and I couldn't imagine going back to being a normal Arrancar without him.

"Wait! Tesla!"

My shout caught his attention, and he halted, turning back towards me. I couldn't read his expression very well, but he wore a thin mask of urgency and purpose. "What is it?"

I stopped a couple of feet in front of him, trying to meet his gaze. Doing so was easier than it was the first time. Even so, just his remaining eye was difficult to hold for long – I had a feeling that with both still intact, I would have twice as much trouble looking at his eyes.

"Let me hear it again."

"What?" Tesla sounded like he didn't know what I was talking about, but a slight change in his countenance betrayed a hint of recognition.

I tried, to little avail, to find the right words. "You have something."

Tesla appeared startled for a moment, but he soon relaxed. He looked as though he would say something in response, and his gaze dropped to the ground. However, he remained silent, only holding one arm across his chest as though to protect something. Right now I was very aware of what that something was.

"I promise I won't hurt you," I assured him softly. Tesla cautiously lowered his arm.

Slowly, carefully, I raised a hand to him and pressed my palm against his chest. Sure enough, the steady beat of his heart responded, gradually calming down as Tesla grew used to my touch. Finally it faded away as he gently grasped my wrist and lowered my hand away from his body.

"Don't say anything to Master Nnoitora," he implored, releasing his grip. If he knows about any of this, he'll kill me."

I blinked, puzzled. "What do you mean, he'll kill you?"

Tesla still wouldn't meet my gaze as he brought a hand to his face, fingering the concealed place where his right eye should have been. "Master Nnoitora did this."

"What?" I struggled to hide my shock. Even while witnessing the volatile Espada tower over those two other Arrancars, I never imagined that he would actually attack his own Fracción. "How can he do that?"

Tesla didn't respond. "He's expecting me. I have to go." He pivoted and continued in his previously intended direction, almost at a run.

"Wait! Please don't leave!" I started after him, but soon realized it was futile. "When can I see you again?"

No reply. Helpless, I sank to my knees as he disappeared into Las Noches.

Alone. A strange, alien feeling gripped me like a giant claw, and I crossed my arms against my front in an attempt to quash it. Perhaps this was the loneliness Tesla constantly experienced; he was Nnoitora's sole Fracción in the first place, and the value of even that was crushed by the fact that Nnoitora was the only other Arrancar with whom he regularly came into contact – Nnoitora, who had the boundless fury even to hurt his own Fracción. For Tesla to bear that burden on his own was unfathomable to me. And that, painful as it may be, must have been magnified ten times over by his possession of a real, living heart, intensifying his isolation with every beat…

I shook my head, suddenly aware that there were tears on my face. Was this really a depressing enough issue that I had to cry over it? Tesla was the one with the heart, not me – it was simple enough to hear it in his voice whenever he spoke. Nevertheless, I stayed on the ground, waiting for my mind to console itself. How could I be crying? For another Arrancar, no less. It only made it worse knowing so well that Tesla was even more capable of these emotions than I was. I was just hollow in the middle – an Arrancar with the unmistakable space in my torso signifying that I had long since lost my own heart. Yet I somehow was so concerned for Tesla, when I should be relieved that I didn't have to carry the same burden as he did.

Unsure of what to do, I let my tears slow to a stop before rising to my feet and returning to the inside of the great building. I told myself not to go and search for Tesla on my own, as Nnoitora would be inevitably keeping an eye on him. I'd have to wait patiently until luck was on my side and the two of us would cross paths again. The thought of such an occurrence lightened my spirits a little, causing me to wonder almost condescendingly at myself. I was actually looking forward to coming across another Arrancar. Perhaps if I had a heart as well, I would be capable of noticing less weight on my shoulders and more carefree contentment at the concept of eventually seeing Tesla again. As just a Hollow, I couldn't feel this happiness quite as a cutely, though a trace of it graced my steps. Maybe by the time I encountered Tesla, I would have my emotions sorted out, and I'd have an inkling of how to protect his precious heart. After all, I had vowed not to hurt him, and I intended to uphold that vow whether I liked it or not.

Most of all, once more I would feel his near-living warmth. Once more I would hear his quiet voice. Once more I would rest my being in the powerful beating of his heart – the last heart in Las Noches.