"Let silver and steel be the essence. Let stone and the archduke of contracts be the foundation." Ritsuka Fujimaru's voice echoed throughout the summoning chamber as she recited the first lines of the ritual.
It was difficult for Nikola Tesla to see beyond the small pool of light where they stood together. An inky abyss surrounded them. Did the cavernous room have walls? Did it drop off into nothingness? His mind knew the answers from his earlier observations. The shadows, though, teased at his imagination.
Leonardo Da Vinci had explained that the room's cavernous design was intentional. While their forms were close enough to that of mortal humans, other Heroic Spirits looked like something else entirely. He could best describe them as having stepped out of the oldest Serbian epic poems. Summoning a hero only to have them manifest halfway through a wall was a waste of time and resources.
Ritsuka stood unyielding at the edge of the ritual circle, her feet shuffling to bolster her body against the surging winds and mana. She grit her teeth and beared down as a sharp gust blew back her red hair.
The rapidly shifting atmosphere failed to unsettle Nikola. His shoulders remained relaxed, his eyes keenly watching the scene playing out around him. If anything, the experiment felt faintly nostalgic.
"Reinforced power levels are optimal! You're cleared to complete the ritual!" Da Vinci's voice remained intense, despite the tinny speakers Edison installed in the chamber.
"From the Seventh Heaven, attended to by three great words of power, come forth from the ring of restraint, protector of the holy balance!"
Hot blue energy arced up from the floor, first focused on the carved circle, then straying wider throughout the room. Nikola instinctively raised his arm to shield himself. While his body would absorb any magic backlash from the ritual, physical debris would still hit like a punch from Kintoki. Ritsuka's body tumbled to the floor beside him.
Then, silence. The room was still.
"Report?" Da Vinci's voice crackled through the speakers.
Nikola lowered his arm, quickly examining Ritsuka from where he stood. No visible injuries. Her pride was another matter. With her grim frown, the girl looked more frustrated than scared. That was a welcomed disposition compared with the results of previous experiments.
He approached the ritual circle, scanning the concrete floor as the chamber lights flickered back on. Several mana prisms littered the floor, their dull glow lighting up the dissipating fog; fascinating that the unexplainable still managed to take on geometric forms.
"Master managed to summon physical mana," he described, stepping carefully through the scattered prisms. They faintly pulsed as he moved past. "I didn't witness a servant manifestation. Did one appear in your readings?"
"Nothing remarkable. Same as last time."
Ritsuka groaned as she patted herself down, quietly cursing as she noticed the winds had knocked out her ponytail.
"I don't understand, Doctor Lightning. I really thought someone would hear us," she complained, reaching for her hair tie. "Not even redirecting power from your generator helped. How are we supposed to find new servants to join us if no one wants to listen?"
If her young face didn't give away her immaturity, the tone of her voice would have confirmed it. One day she might make for an excellent lab assistant, but for now Ritsuka Fujimaru was an experiment unto herself.
"Remember what I told you earlier: failure is part of the scientific process," Nikola stated, hoping his wisdom would reshape her perspective. "To fail is to be human. Overcoming the concept of failure would mean overcoming your own humanity."
"I guess my gripes seem silly when you put it that way." He could hear the sheepish smile in the young woman's voice. An improvement. "Do you still fail at your own experiments?"
He folded his arms and turned to leave the chamber.
"Not anymore."
Chaldea's research labs had seen better days.
There reportedly had been more mortal scientists on the payroll before the Grand Order. An accident thinned their numbers, leaving the organization with an overworked skeleton crew. All remaining staff were required for operations, leaving little room for study and development.
Few of Chaldea's servants opted to use the labs. More traditional intellectual heroes - spellcasters, mystics and the like - preferred the ambiance of dusty libraries and dark alcoves. They didn't have the same standards for observation and documentation as their modern counterparts. That left Nikola alone, with only his thoughts keeping him company among the brightly lit rows of empty desks and workbenches.
On his tablet he jotted down today's observations: AC current was increased to the summoning space as an ethereal catalyst. No modern servants manifested. Correction: no servants manifested. Mana was generated. Energy output versus rate of mana return would have to be calculated further.
He tapped his stylus against the desk and frowned. Servant memories could be faulty, but he was certain he had been summoned multiple times now.
First to London, although his heroism was limited to only stalling disaster.
Then to the battlefields of America, where he was able to dramatically turn the tide in Chaldea's favour.
Now to Chaldea proper, finally able to analyze humanity's current crisis.
Few others from his era followed. Originally, he suspected his own existence was the cause. The Throne of Heroes recorded him as a Pioneer of the Stars, a disruptor who forced humanity into a new age. Perhaps the fissure in human development he created ran so deep that no others from his lifetime could be summoned.
The evidence against that hypothesis was his... contemporary.
"A great American writer once said that Insanity is doing the same thing over and over again and expecting different results."
Nikola slowly placed the stylus down and looked up at Edison. The other man loomed tall above his desk. In all of his predictions of the future, Nikola never imagined that his rival would return to life as a postmodern nightmare with the head of a lion, the physique of a Renaissance sculpture and the soul of a jackass.
Actually, he had correctly guessed that last one.
"That great writer never said that," Nikola calmly declared, keeping his composure as stiff and formal as possible.
"Nonsense," Edison growled, his fingers digging into the far edge of the desk. "Next you'll tell me that at no point did he write Never attribute to malice that which is adequately explained by stupidity."
It was obvious to Nikola what writer Edison was trying to quote: Mark Twain, a satirist both of them had known personally. While Nikola could dismiss the first misattributed quote as self-deprecating nonsense, that second one made Twain sound like a misanthrope. If this is how the modern age remembered their era, no wonder so few heroes from it had answered Chaldea's pleas.
Not that Edison deserved that insight. Instead, Nikola tossed back his head and let out his deepest, most unsettling laugh.
"You're a fool!" he spat, sparing no words. "A corrupted fragment of history who can't properly remember the world he came from!"
The reaction was intentionally obtuse. The attack hit its mark: Edison took a step back, scrunching his brow in what Nikola could only assume was a scowl.
"This is why you don't have friends," Edison grumbled, then fell silent.
Nikola imagined at that moment that the lab had a pendulum clock instead of a digital one, its rhythmic ticking accentuating the uncomfortable pause.
Edison yielded first: "Did the Director consult you about the blip they found?"
"No." Nikola's attention had returned to his tablet, updating a spreadsheet with today's data. "Of course a cretin like you would describe a complicated space-time phenomenon as a blip."
"Today's readings tracked down a slight singularity shortly before the Norman Conquest," Edison countered, emphasizing the specific details as if he had something to prove. "There were reports of a fireball in the sky, but I determined those details matched with the proper timeline."
"Then the matter sounds concluded," Nikola remarked.
He, of course, would have asked more questions about the readings. Edison's clarifications confirmed the singularity's coordinates as 1066. A comet appeared that year shortly before the Battle of Hastings. King Harold Godwinson's death in the conflict had been particularly strange: a single arrow through the eye and then brain. It was so absurd that scholars of that age justified it as an act of God heralded by the earlier comet.
Given his own relationship with that comet, Nikola knew its appearance in the singularity carried more weight than Edison realized.
Edison stood at the other side of the desk, probably expecting praise or validation. Pathetic.
"Our conversation is over." Nikola glared at Edison over the edge of the tablet.
Without a final whimper of defeat, Edison left the lab.
Nikola soon followed.
"The fireball in the readings is 1P/Halley!"
Nikola proclaimed his conclusions as he marched through the control room's sliding doors. All eyes were on him as he briskly made his way to the console manned by Roman and Da Vinci.
Da Vinci could easily be his equal in more ways than one, dressed more for style than function and completely unfazed by his announcement. Roman, easily the more haphazard of the two, jerked back in surprise. The sudden movement knocked over his mug, splattering coffee down his lab coat. Only Da Vinci's reflexes stopped the mug from falling to the floor and scattering.
"Huh?" Roman looked up from his soaked sleeve. Anxiety rippled through his voice like a wake on a calm lake. "Come again?"
"He's referring to Halley's Comet," Da Vinci calmly clarified. She placed the mug back down on the desk and waved over a nearby staff member to mop up the spill.
"If you want to use the common name, then yes," Nikola continued. Da Vinci must have been simplifying for Roman's benefit. "The celestial body that races parallel humanity's development. The cosmic herald of mankind's success and destruction."
"It arrived too early in my lifetime for me to remember it." Da Vinci offered an underwhelmed half shrug. "Although I did read il Platina's retelling of the comet's 1456 visit. Apparently the church tried to excommunicate it."
"An absurd event like that is why this singularity is more dire than the early conclusions suggest," Nikola explained, illuminating his hypothesis with further details. "If an enemy destroyed the comet or managed to alter its orbit in 1066, then all events connected to it are forfeit. Human history is shaped by superstition. Remove the source of the superstition and the 2nd millennium that we remember will not happen."
Da Vinci rested her hand against her face, her sharp gaze reflecting a growing interest in the situation. Roman merely shook his head.
"Do you really think that's possible?" he asked, rubbing the side of his head. "Shooting a comet down from the sky sounds like a mad scientist's scheme."
"I am that mad scientist. That's why Chaldea needs to send me into the singularity with Master." Nikola suppressed a flinch, praying that Edison didn't hear him utter those words or the ones that would soon follow. "Of course, there's another opportunity here I need to address. A chance to prove the catalyst theory we've been discussing."
Da Vinci folded her hands together and leaned forward. Nikola recognized the bright spark in her eyes. It was the same drive that united the two of them under the banner of Pioneer of the Stars.
"Go on," she urged.
The bright light of the rayshift faded.
It took Nikola's eyes seconds to readjust to the singularity. He knew from experience that it would take Mash and Ritsuka slightly longer to reacclimatise. That gave him enough time to properly assess their situation before debriefing the young women about what was going to happen next.
Da Vinci rigged their entry coordinates to his calculations: an empty field, preferably in the early evening, out of sight of any locals. It didn't take a genius to understand that cultural interference wouldn't have great outcomes. The surrounding grass swayed as an unseasonably cold gust of wind rolled through. Above them was the comet, a bright glittering diamond against the backdrop of the dark blue sky.
Their paths had crossed again. Nikola closed his eyes and took in a deep breath; the air smelled fresh and peaceful, in direct contrast to his own conflicted emotions. Halley's Comet passed only once in his mortal life, taking one of his closest friends with it. If a more malicious Master commanded him to shoot it down, he would have gladly taken the shot.
The light casual conversation behind him indicated that Ritsuka and Mash had fully arrived. He turned to face them, allowing his cape to billow wide in the night breeze. Ritsuka, Chaldea and humanity itself needed him to push his uncertainty aside for the moment.
"We need to act quickly," Nikola commanded, gesturing at a supply crate at Mash's feet.
There was a clicking sound, then a low hiss as Mash pulled open the crate's lid and dropped it to the ground. Ritsuka leaned over to peek at the carefully packed contents, her eyes slowly growing wide.
"Wait, is this a battery?" she asked, then looked back at him as she came to a further realization. "Are we continuing the experiment?"
"Yes, but we're continuing it here with a hand-cranked alternator, not a battery," Nikola explained, proudly resting his hands on his hips. "I wouldn't attempt an experiment with mundane DC technology. I must confess that I haven't been the most honest with you, Master. My lousy excuse for a rival loves to spread rumours that I crave isolation. While I appreciate the more obnoxious residents of Chaldea leaving me alone, those rumours are a lie."
"You did have friends, Doctor Lightning!" Ritsuka proudly concluded, a beaming grim growing on her face.
Nikola grimaced. What other lies did Edison feed to her? Ritsuka must have realized her misstep; the young woman blushed, her gaze darting over to an equally startled Mash.
"I mean, I just assumed you had friends you didn't talk about," Ritsuka said, backpedaling slightly. "A life without friends seems lonely, even for a genius."
That introspection got a frown out of Nikola. He sighed and shook his head.
"Of course I knew other geniuses in my lifetime," Nikola revealed, once again hoping his insights would reshape Ritsuka's outlook. "Allies who wanted a better future for humanity. Any of them would proudly stand with Chaldea. I have a new theory on how to reach them and I'm certain that we will contact someone tonight. As I told you, I don't fail at my experiments. Not anymore."
"But other than the bat-" Ritsuka started to say, then corrected herself. "I mean, alternator, we didn't bring a catalyst."
"We didn't need to bring a catalyst!" Nikola proclaimed as he raised his hand towards the night sky overhead. "Behold, Halley's Comet! Mankind's immortal companion in the heavens! Its journey is intertwined with the lives of countless Heroic Spirits! One of them was a close personal friend of mine."
Ritsuka stared blankly at Nikola's showmanship. Mash, however, softly smiled as she pulled out the alternator parts and laid them on the grass.
"I remember reading once that you knew the writer Mark Twain," Mash said, her eyes lit up as she speculated further. It was impossible for her to hide the excitement in her voice. She must have read his work. "He claimed that his life was linked with the comet. He was born during the year it visited and then died when it returned."
"I knew him as Sam, but otherwise you are correct," Nikola confirmed for Mash, then looked over at Ritsuka.
The other young woman's eyes darted between Mash and Nikola. She still seemed confused, as if the others were sharing a joke she hadn't gotten yet.
"Sam was the friend who first gave me the nickname you use now," Nikola explained to pull Ritsuka back into the conversation.
"Right, Doctor Lightning," Ritsuka reflected to herself with a smile. "Are you sure your friend was recorded in the Throne?"
That was an excellent question. The idea of a mystical place that recorded the greatest feats of humanity was beyond even Nikola's mortal understanding. This whole time, he had been acting on the assumption that others he knew in life were recorded as heroic spirits. Edison misremembered quotes that he claimed Sam said. That could mean that there wasn't an accurate record of Sam in the Throne of Heroes.
On the other hand, Edison was an idiot.
"I have one piece of evidence to go on," Nikola finally proposed. "Sam once wrote: "I have never seen what to me seemed an atom of truth that there is a future life...and yet-I am strongly inclined to expect one." I didn't know the Throne of Heroes by name in life. None of us did. However, I wonder if Sam sensed its existence without having the proper name for it."
Ritsuka rolled up her sleeves. She didn't need any more convincing.
"Doctor Lightning!" she proclaimed, jumping up to her feet. "I'm ready to try the experiment again."
Chaldea's labs were livelier than usual. Edison stood in the doorway, dumbfounded at the scene in front of him.
Tesla, Ritsuka and Mash sat together at one of the desks. The three of them passed a book back and forth, reading out various passages while laughing. A pot of fresh coffee sat between them.
Food and drink in the lab was in strict violation of the established lab rules. Despite all of Edison's instincts, calling that out at this moment felt wrong.
There had been a follow-up investigation of the 1066 singularity. Edison wasn't invited on the mission. He was smart enough to realize why: Tesla helped organize it, apparently spurred on by a crack theory about a "death ray" that could "shoot down the moon" or other uninspired nonsense along those lines.
It wasn't clear to Edison exactly what happened on the mission, but it must have been profound to have such an impact.
Grief can take care of itself, but to get the full value of joy you must have somebody to divide it with. - Mark Twain
Author's Note
This story was written for Neo as part of the Fateverse Summer Exchange.
Neo's top character request was Nikola Tesla. I went looking for what Tesla-focused fics existed and didn't find much. My sense of nerd justice went into overdrive and I decided... I was going to write a Tesla fic because all fans deserve to read a thoughtful story about their fav character.
Special Thanks: Adet, Maikeru, and Rob for beta support. My local sci-fi convention friends for helping me find the Tesla-related urban legends and true stories that inspired this story.