The Guarantor

The archives were coated in a decade’s worth of dust. Gregor von Wallenstein held the lantern himself and walked between the towering shelves. No one knew the Grand Duke had personally descended into the records hall in the dead of night. He had not announced it.

Apprentice roster, Imperial Year 602. The leather binding creaked in his grip. Gregor flipped through the pages and stopped at one entry.

Name: Kael. No surname. Estimated age: twelve. Origin: border village of Trent, St. Michaela Orphanage.

That much he already knew. The problem was the next line.

Not just anyone could become an apprentice of the Grand Duchy. For a commoner child to enter, there had to be a guarantor to vouch for their identity, and that guarantor had to leave a signature. Ten years ago, someone had signed in this very column.

Someone who had brought an orphan boy all the way to the northern edge of the empire and left him standing at the gates of the family with the highest sword in the realm.

Guarantor signature field.

The ink had bled, perhaps from water damage, and was smudged beyond recognition. Only the first letter remained legible.

Le.

Gregor stood there for a long time without closing the roster. Vice Commander Valter’s report refused to leave his mind.

Five of us couldn’t even cross blades with him. Without using aura, he made my own aura feel shameful. He hides his master’s name as if protecting it.

Beside the roster, Gregor had also stacked another set of documents—every report from the past ten years that mentioned Kael’s name. The more he read, the stranger it became.

Age fifteen: rescued three knights during a demonic beast subjugation—minor injury to self.

Age seventeen: defended a carriage during a bandit extermination—minor injury to self.

Age nineteen: solo search and rescue during a snowslide burial—rescued seven people alone, no abnormalities.

Every single time, it was either a minor injury or no abnormalities at all. In ten years, he had never been injured badly enough to earn recognition for merit, nor had he ever come close to death. On paper, he looked like a lucky mediocrity.

But reading between the lines told a different story. Where three knights should have died, a commoner apprentice walked away unscathed. He had dug through snow that had buried seven people all by himself.

Luck could not be that good for ten straight years. Ten years of perfect luck was not luck—it was design. Strong enough not to get hurt, clever enough not to be noticed.

Who could create such a child? How many masters in the empire could forge that level of skill at such a young age?

Gregor counted on his fingers.

Seven Sword Masters. Among them, four had the temperament to teach the sword. Ten years ago, the one who might have passed through the south dressed as a wanderer—

None of them.

All seven had clear records of their movements. A Sword Master’s whereabouts were a matter of national defense; the empire tracked and documented them. There was only one person whose movements had never been recorded.

The one who could no longer be recorded.

“……It can’t be.”

Gregor pushed the thought back onto the shelf. It was dangerous for an old hunter’s intuition to outrun the facts. He had to gather the facts first.

The next day, Gregor left the castle under the pretext of a hunt. He took only four escorts and headed not for the hunting grounds but for a remote farmhouse on the outskirts of the outer village.

The retired former Knight Commander, old Oswald, was scattering feed for the chickens. When he saw the Grand Duke, he tried to straighten his back.

“Don’t. You’ll break something.”

“……To think the Grand Duke himself would come to inspect a chicken coop. Have you come to arrest this old man?”

“I’ve come to talk about old times. Ten years ago. You took in one apprentice. His name was Kael.”

The feed stopped falling from Oswald’s hand. After a long silence, the old man closed the chicken coop door, sat on the wooden bench, and finally spoke.

“……I always knew someone would come asking one day.”

“You remember, then.”

“How could I forget? A thing like that happens only once in a lifetime.”

The old man’s eyes traveled back across ten years.

“It was a night of heavy snow. Some wandering swordsman stood in front of the castle gate with a child. He looked like a beggar, yet when four gatekeepers pointed spears at ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠him, he didn’t even blink. He asked them to call for me. He didn’t give his name—just said, ‘He’ll know when he sees the sword.’”

“Did you see the sword?”

“I did.”

The old man looked down at his own dry palm.

“He drew it only a handspan from the sheath. It was grey. There is only one sword in the empire with a grey blade. The one I had only heard of in rumors… that…”

“Do not speak the name,” Gregor cut in.

It was a name he was not yet ready to hear. Oswald nodded and continued.

“That person told me: ‘Take this child as an apprentice. Do not ask about his origins. Treat him exactly like the other apprentices. Neither favoritism nor mistreatment. And—’ I remember these words down to the last syllable.”

The old man swallowed.

“‘One day, the North will stand on the strength of this child alone. Until that day comes, let him simply be a boy who sweeps the yard and polishes swords.’”

Only the sound of chickens pecking at feed filled the yard.

“……And?”

“What was the child like? At that time.”

“……He was a strange child.”

The old man glanced toward the chicken coop as he chose his words.

“When we take an apprentice, we hand them a wooden sword on the first day to test their aptitude. I gave one to that boy as well—but the hand that took it was already perfected. A twelve-year-old hand. So I exchanged a single blow with him, and he deliberately swung it clumsily. His imitation of clumsiness was so precise that anyone who didn’t know better would have seen nothing but a complete novice.”

“So he had even learned how to hide.”

“Yes. He was a child who learned how to hide before he learned ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠the sword. That frightened me most of all. Who would teach a twelve-year-old such a thing? What circumstances would force someone to teach it?”

“After receiving my signature on the guarantee, that person left immediately into the snow. Northward. In the direction of the Grey Boundary. That is all. I did exactly as I was told. I treated him the same, showed no favoritism… though I could not prevent the mistreatment.”

Gregor rose from the bench. He asked his final question with his back turned.

“Why did you not report it? In all those ten years.”

“There was nothing to report. A nameless wanderer left a child in my care—that is all. However……”

Oswald paused to choose his words.

“Your Grace. This old man has seen one sword in his lifetime. That single handspan of grey I saw that day was the quietest and most terrifying blade among all the swords I have ever witnessed. If that sword’s final direction was the Grey Boundary—then the fact that nothing has happened in that direction for the past ten years… could that truly be coincidence?”

When Gregor returned to the castle, he opened the iron chest deep inside his study. It contained secrets seen only by the heads of the Grand Duchy. From the very bottom, he pulled out a yellowed military report.

Imperial Year 602. The final report of the Grey Boundary Great Expedition.

Ten years ago that year, the Grey Boundary had burst open. A demonic beast wave had swallowed two border fortresses. Thirty thousand northern troops had stood in its path, and Gregor himself had taken the vanguard.

And at the deepest point—the military report recorded that day as follows:

An unidentified swordsman.

Gregor remembered that day not through the written words but with his own eyes. It was the third day since the two fortresses had fallen. The demonic beast wave showed no end, and the northern army’s lines were pushed back a hundred paces each day. Even Gregor’s own axe had lost its edge.

It was the dawn when he had begun mentally drafting the first line of the defeat report.

Then grey light rose from within the fog. It was too quiet to be called sword light. Without sound, without battle cries, a single streak of grey split the heart of the wave. A lone figure walked into the fissure.

Into the middle of tens of thousands of demonic beasts, as if walking through a barley field.

And half a day later, the wave stopped.

They had survived without knowing why. For ten years. It simply stopped, so they lived. Because they lived, they protected the North.

The one who entered never came out. The army recorded him as ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠unidentified. All Gregor knew was that he owed a debt to that grey light that he could never repay in his lifetime.

The army had written it that way, but everyone who had stood in the vanguard that day knew the truth. Everyone who had seen the grey sword light cleave through the fog knew.

They simply could not write it down. The moment they recorded that the empire’s Sword Master had entered alone without imperial command and never returned, it would become a national funeral.

Sword Master Leonhardt.

The strongest in the empire. Missing for ten years.

And the grey sword that had stood before the gates of Wallenstein on a night of blizzard, just before that disappearance.

Gregor opened the apprentice roster beside the military report. The signature blurred by water. Only the letters Le remained.

Next to it, in the guarantor’s seal column, a single crushed emblem rose into view beneath the lantern light.

A falcon perched on a blade.

It was the same crest that had been engraved on the back of the man who had walked into the Grey Boundary ten years ago.

It was the Sword Master’s crest.

“……This is insane.”

A curse slipped from the Grand Duke’s lips. There were no other words that fit.

The boy who swept the yard and polished swords.

The commoner escort his own daughter had used, humiliated, and driven away for ten years.

That was the one the Sword Master had personally planted in the North—

One day, the North will stand on the strength of this child alone.

Gregor placed both the military report and the roster back into the iron chest and locked it. His hands moved slower than usual.

Did anyone else know this truth?

The grey sword that the Crown Prince was investigating. The report that the Imperial Intelligence Agency had already been deployed all the way to Valk. If those bastards connected the dots first—

The Sword Master’s successor would be reclaimed by the imperial family. That was the law, and the one who held that law was his daughter’s fiancé.

Gregor organized several thoughts on the spot.

First, this chest would remain closed for the time being.

Second, he would station men around old Oswald’s farmhouse. The old man’s mouth was heavy, but the Imperial Intelligence Agency knew far too many ways to open mouths.

And third—there was one thing that settled itself whether he wished it or not.

He could no longer treat that child as a mere commoner escort.

The grey light to which he owed a debt had returned after ten years, now bearing interest.

At dawn, a southbound carriage stopped in the inner courtyard of the Grand Duke’s castle. Elise was dressed for travel—not in a dress, but in an outfit suited for a swordsman. A sword hung at her waist and her hair was tied back.

Her escort consisted of Valter and four plain-clothed knights.

“I have told the Crown Prince’s side that you are taking a period of recuperation. At the southern hot springs.”

“……Thank you, Father.”

“There is no need for thanks. I am sending you because I cannot stop you.”

Gregor noticed the leather cord around his daughter’s neck. Its end was hidden beneath her collar, but he did not need to ask what hung from it. He had already heard the head maid’s report about the Wolf Fang that had disappeared from the drawer two months ago.

“Are you going to return it, or to retrieve it?”

Elise covered the spot above her collar with her hand. After a long moment, the answer came.

“……I can only return it if there is someone willing to accept it.”

Gregor looked past his daughter’s shoulder at the southern sky. The grey clouds that had lingered in the same place since yesterday had descended a little lower today.

Go and hear his answer. He had pushed her forward with those words only yesterday. ‍‍‌‌⁠​​⁠‌​​‍​​‍​‌​⁠‍‌‍⁠⁠‌⁠‌‍‌‍‌‌‌‍⁠​‌​‌​‌‍‌‌‌⁠‍​​‌‍⁠‌‌⁠⁠Yet in the span of a single day, the Grand Duke had learned exactly who the man his daughter was going to meet truly was.

Should he tell her?

What would happen if he did?

The moment she learned she was chasing after the disciple of a Sword Master, her apology would lose all its value forever. An apology offered while believing him a commoner was genuine. An apology offered after knowing his status would be an investment.

Gregor chose to keep his mouth shut.

“Elise.”

“Yes.”

“If you find yourself needing to kneel, then kneel. Not as the knees of Wallenstein, but as your own. Do not think of the family.”

Elise, who had been about to climb into the carriage, turned back to look at her father. She seemed about to say something, but in the end only bowed her head deeply.

The carriage passed through the castle gates. The wheel tracks stretched long across the snow toward the south.

Gregor stood in the inner courtyard until those tracks disappeared from sight. Then, in a low voice that no one could hear, he murmured.

“Leonhardt. How am I supposed to repay this debt?”

The name buried in the Grey Boundary ten years ago gave no answer.