A wedding ring.
When Isaac first entered Helmut as a son-in-law by marriage,
He had liquidated all his assets, preparing only a single dowry.
Even so, the ring was too humble a gift to suit the eldest daughter of Helmut, worn on her left ring finger.
On the day of their divorce, the couple exchanged rings before the gods—
A symbol of severance and dissolution.
The "Severance Ring" was an oath that declared their complete separation.
That was why the wedding ring Isaac currently possessed was not originally his.
It had once adorned Liana's ring finger.
So why was it suddenly reacting like this?
The question surged through Isaac's mind, but he didn't have time to dwell on it.
"Gah!?"
The ring had become too hot to hold.
He dropped the glowing ring to the ground.
It continued to emit light and smoke, asserting its presence.
Magic from the Tower arced through the air, targeting the ring.
Clack!
Isaac instinctively gripped his sword with both hands.
A sword, like a bird spreading its wings, burst forth with spectral energy to intercept the Tower's magic.
—Kyaaaaaaaah!
The scream from the spectral aura seemed to resonate with Isaac's emotions.
Logically, he knew he shouldn't confront it head-on.
But Isaac didn't want to see the ring destroyed.
The swing of his sword cleaved the magic.
Like stars bursting in the night sky, mana spilled from within, scattering traces of power everywhere.
"Urgh!?"
The sheer amount of mana was so overwhelming that, even with a single swing, Isaac's arms trembled.
"Mu-myeong! Go stop the Tower Master!"
At the Grandmaster's shout, Mu-myeong was already in motion.
Another burst of light soared into the sky and came hurtling down toward them again.
"For now, retreat. Facing that magic head-on is unwise."
Who knew how many mages had been consumed to cast that one spell.
While they may be ineffective in close combat, a mage's firepower is not to be taken lightly.
"…I cannot retreat."
But Isaac did not back down.
He had an instinctive feeling that the ring held the secret to regression.
And emotionally, he couldn't let it go.
"It's coming again! It's coming again!"
Sharen's urgent voice cried out as she pointed at the sky.
Isaac, with trembling hands, gripped his sword once more, prompting a sigh from the Grandmaster.
"Haa… How weak I am to my disciple. What kind of teacher does that make me?"
She pushed Isaac back by the shoulder, stepping forward.
Placing her hand on her greatsword, she steadied her breath and looked up at the sky.
"Learn to let your master handle things once in a while."
With a lighthearted grumble toward her disciple, the Grandmaster drew her sword.
A single stroke of light, far more brilliant and dazzling than the stars lit by the Tower Mages, poured forth and illuminated the dark night.
***
The stars no longer fell.
Two massive masses of mana had been split apart,
And the surroundings were now so saturated with mana that one's eyes stung slightly.
Even Isaac felt a flutter of excitement as he waved his hand and sensed the mana in the air.
"Wow."
Sharen, too, was marveling at how the crimson aura had become even stronger.
Just then, the Tower Master Regant and a group of mages—moving a bit slower—arrived in a flurry.
"What's going on here?"
Pointing his staff, he radiated killing intent.
Regant looked especially furious, running a hand through his hair as he glared.
Each word he spat was laced with open hostility, as if grinding his teeth.
"We treated you like a guest, and you turned out to be a damned thief.
Even lived under our roof. Did you really think we were that stupid?"
"You're under a strange misunderstanding."
At Isaac's calm reply, Regant hesitated for a moment.
"I get that you're angry, but if you calm down, you'll realize your logic doesn't add up."
Isaac glanced to the side.
At some point, the Grandmaster and Mu-myeong had placed their hands on their swords.
That likely meant: If the other side showed hostility, they'd behead them immediately.
"…"
Regant noticed that too.
He swallowed hard, realizing death was right in front of him without his knowing.
His overheated mind quickly cooled.
The staff pointed at Isaac slowly lowered, now pointing toward the ring lying on the floor.
"That ring reacted to magic. That alone means you already owe us an explanation."
Feigning calm, Regant spoke sharply once again. However, his voice was clearly restrained, showing he was controlling his emotions.
Isaac calmly looked at the ring and asked,
"Let me confirm just one thing. Is it possible the magic malfunctioned?"
Honestly, that seemed like the most likely possibility. But Regant firmly denied it.
"It could've happened if it was just once. But our magic hit that ring precisely twice."
"..."
"If it was a magic error, the spells would've gone in different directions. But the spells clearly targeted your ring… so there's nothing wrong with the magic."
In conclusion, the mana core was connected to the ring.
"Alright then."
With that final confirmation,
Isaac, who had considered every last possibility, nodded calmly and spoke.
"It seems like the picture is finally coming together."
The mystery of his regression, which had once seemed so unclear, now finally began to unveil.
***
The place they entered was the Magic Tower.
Vivian had said that the cylindrical Magic Tower now only stood as a symbolic structure with no real practical use,
But in reality, it was much deeper than it looked.
Behind the tower, buildings had been constructed over sunken ground.
So, instead of going up to enter the tower, they actually had to go down.
Surprisingly, the actual entrance was underground.
Upon entering the underground, the place radiated an atmosphere of mystery and gloom, as if it were concealing the secrets of the Magic Tower.
Regant, lighting his hand with a small flame, stepped onto a massive magic circle etched into the floor and said,
"That's where the mana core falls from above."
His voice echoed along the walls of the long cylindrical building. He shone his light upward, but the darkness still hid the ceiling—it was that high.
"We perform magic here using the mana core that falls from above. The core's mana is so vast that it's not something a person can easily handle."
"..."
"The term 'mana core' is just a name. It's actually a condensed mass of mana—"
"Hold on a second."
Something about this was strange.
"If it's that difficult for a person to handle… why did you assume someone stole it?"
When Isaac cut in, Regant scratched his head awkwardly and replied with a wry smile.
"If that much mana just suddenly disappears, what else would we think? Normally, homeowners believe their house is safe until a thief slips in and steals from under their nose, right? It's kind of like that."
"..."
"And with strange sorcery showing up… if someone had used that much mana for magic, it would've left traces. So, the only explanation we could come up with was that someone stole it. And, well… it's not impossible to move it. You'd just need about half a dozen mages to die in the process."
The mages had racked their brains over the missing mana core, and in the end, their "answer" was that someone had stolen it by some unknown method.
But to be fair, there wasn't any other explanation.
"However, after hearing your story, I think I finally understand."
Having listened to Isaac's explanation of his regression, Regant nodded and looked at the ring.
The ring had lost its glow and returned to its original appearance.
"The mana core wasn't stolen. It had already been used. To rewind the world once."
And most likely, the one who used that magic was…
"Me, I suppose."
Regant awkwardly scratched his cheek.
"If what you say is true, then it would've been about ten years from now. The me from that time must've used the spell. To prevent humanity's extinction."
Of course, that assumed Regant hadn't died. But he seemed fairly confident.
Confident that he had survived.
"Well now, does this mean we owe you our lives?"
Regant asked jokingly, to which Isaac replied politely,
"We're even, I'd say."
"Haha… In any case, thanks to your efforts, it's true the current situation is much better than before."
Regant added that even the mages hadn't sensed the danger at the time.
He knew well that peace was never something achieved without cost.
"Then, does that mean the regression magic was successful? Though it's a forgotten history no one remembers, it seems everything has gone well so far—."
"There are still unanswered questions."
He now understood the reason for the regression.
He knew that the Tower's magic had been used as humanity's final bastion to save them.
"But I need to know why it was me. And why our wedding ring was used as the medium."
"..."
If dying with Liana's wedding ring was the trigger…
Then why didn't Liana's regress, even though she was wearing the ring when she died?
"Could it be that the regression was limited to just me?"
Isaac asked with a hint of hope, but Regant shook his head.
"That's not possible. The spell activates through death. If that were the case, wouldn't you have had to die at the exact same moment for both of you to regress?"
"..."
"Let me see the ring."
Isaac placed the ring in Regant's palm.
Regant looked it over and muttered to himself.
"A ring imbued with a spell using a mana core… So this ring came from the future as well. Then if I'm the one who used it, there must be something—."
As Regant muttered on, the group looked at Isaac with somewhat complicated expressions.
"Well, doesn't it feel nice to have everything out in the open now?"
"Those who know about Isaac's regression and those who don't! That's how trust is decided!"
The Grandmaster offered comfort, while Sharen looked smug.
On the other hand, Mu-myeong and Damien wore mixed expressions.
They weren't upset, but they clearly found the idea of experiencing regression firsthand quite fascinating.
And then—
"…It really is here."
Regant murmured as he looked at the ring.
He let out a hollow laugh and explained,
"Most mages have their own ways of—."
"Spare me the explanation. Keep it brief."
Mages had a tendency to ramble with unnecessary details, so Isaac cut him off sharply.
Regant, a bit disappointed, responded concisely.
"There are traces left—of my mana. So it really was true? Honestly, I wasn't entirely convinced."
"..."
So he hadn't believed it completely until now.
"I must've left it behind to help understand the situation. I may not look it, but I'm still the Tower Master. I can see a few steps ahead of others."
Satisfied with the competence of his future self, Regant placed the ring at the center of the underground magic circle.
"The record is readable right away. Thanks to someone, there's an abundance of mana right now."
Since the spell to locate the mana core had been cut off early, there was plenty of mana left to work with.
There was no hesitation.
Isaac slowly stepped forward.
Soon, mana began to spread out from Regant's body.
His body remained in place—
But Isaac's vision steadily zoomed in on the ring, and before long, he was completely sucked into it.
***
A narrow altar. An old chair. Dust floating in the air, illuminated by the faded stained glass.
'This place…'
Isaac recognized it.
The capital city of the kingdom, Evergard.
A church managed by Helia Bell, a nun and Jonathan's mother.
However, it was clearly different from what Isaac remembered—it had not been cared for at all.
The only difference was that it was completely neglected—as if the woman who once tended to it had vanished years ago.
'The place where we got divorced.'
Even now, recalling that day left a bitter taste on his tongue.
The blurry scenery gradually began to gain color.
At the center of the church stood two red-haired women.
One of them was—
Liana Helmut, the woman Isaac had eventually laid to rest.
Then the other red-haired woman standing across from her must be—.
"[Sharen, where is Regant?]"
The woman whom Liana called Sharen looked quite different from how Isaac remembered her.
The twin-tailed hair was now tied only on one side, and instead of a bright and innocent expression, her face was filled with cold resolve.
[Why are you here instead of Regant?]
[Because I had a feeling what choice you'd make. I asked Regant to let me meet you first.]
Sharen's voice was full of hostility.
The chill in her blank expression seemed like hatred directed at Liana.
But Isaac, who knew her well, could see that the true emotion buried beneath was worry.
[You said you'd send Isaac back.]
[Sharen—]
[I'm against it, Sister.]
[...]
[You should be the one to regress.]
[Sharen, you know too, don't you? Just how many people Isaac has saved as the Silent Sword.]
Sharen fell silent.
She couldn't deny it.
Books written under the name "Isaac" were used as military manuals and served as highly efficient teaching materials.
Even Sharen had learned from them, so she couldn't outright oppose the idea—
[Even so, you should be the one to regress.]
Sharen was resolute.
[You… would do it better.]
At her cold voice, Liana faintly smiled.
It was such a bitter smile that even Isaac, knowing how it ended, felt a tight pain in his chest.
[My little Sisterter, Sharen.]
[…You have to live.]
[Thank you.]
[If anyone must live, it has to be you.]
[This isn't a decision made purely out of emotion. If Clarice were still alive, I would've asked her. But… it's too late now.]
[Sister!]
Riana said nothing more.
She understood why Sharen was saying this, and couldn't reject it outright.
But Liana had already made up her mind.
[Isaac will surely succeed.]
[Now?! You want to act like his wife now?! That bastard's been gone for ten years! Why the hell would you do this for someone you haven't even seen once in a decade—!]
Liana didn't answer.
Because Sharen already knew the answer.
Grit.
[Fine.]
Sharen bit down, and her face grew more expressionless by the second.
[You said the regression magic activates through death.]
Looking at the ring on Liana's left ring finger, Sharen made a cold resolution.
[Then I'll kill you now… and send you back.]
She declared.
[Because… I want you to live.]
(Image)