The Childhood Friend's Oath

"This is bad, this is really bad...!"

A few days after the sea dragon was defeated.

After receiving word, I set sail from Rondine and came to a port in the Grand Duchy of Albatro.

But I had one massive source of anxiety.

"How could I forget to tell him something so important...!"

That's right, I'd forgotten to tell Leo something.

The fact that Eva had fallen for me.

I'd had far too much to do, and personal matters like that had completely slipped my mind.

Knowing Leo, I wanted to believe he'd managed to handle it somehow, but this was a matter of romance between a man and woman. Even a little thing could turn into a huge hassle. And Eva was the Grand Duke's daughter, to boot.

Apparently, Leviathan had appeared shortly after Rondine's fleet arrived and the Grand Duke of Rondine came ashore at the port. That meant Leo and Eva hadn't had a chance to talk at that point. But the problem was the several days that followed.

It was impossible, given Eva's personality, for her to sit still.

"I hope he's handled it without causing any trouble..."

With that thought in mind, I landed in the Grand Duchy of Albatro. Since I was supposedly visiting for the first time, I looked around with apparent curiosity.

Then Leo, who had come to meet me, walked over.

Beside him was...

"Hmmm?"

Eva, chatting cheerfully with Leo.

What? What was going on?

How had they become so friendly? How had they gotten close to each other?

Was this it? Did Leo assume that women naturally came around to him?

Had he interpreted Eva's advances as perfectly natural too? Had he secretly thought, I'm so handsome, I'm amazing?

As I reeled from my little brother's outrageous self-perception, Eva greeted me.

"It is a pleasure to meet you, Prince Arnold. Since my father is busy, I, Evangelina di Albatro, the duke's eldest daughter, have come to welcome you. Please call me Eva."

"Ah, yes. It's a pleasure..."

"You must be tired after the voyage, brother. We have a lot to talk about, but why don't you rest first?"

"Yeah... I was a little shocked..."

Saying that, I headed for the carriage waiting for me.

Eva and Leo apparently had plans after this as well, so the two of them went off somewhere together.

Ah, how sad.

"My little brother has been corrupted..."

"What are you talking about?"

"Oh, Marc. Listen to this... Leo has become a womanizer..."

"I'm curious what train of thought led you to that conclusion, but if memory serves, you're the one who made Princess Eva fall for you, aren't you?"

"Hmm? You noticed?"

"Anyone would have noticed. She was going around asking the knights about you, and that was the face of a girl in love."

"I see. Was it really that obvious?"

Which meant...

I stared hard at Marc's face.

"As you suspected. I already informed Prince Leonart myself."

"Oh, you're useful after all?"

"Did you think I was useless until now?"

"Not exactly. Well, I see, I see. What a relief... That was the only thing I was worried about."

"I'm glad to hear it. The next problem wasn't something I could do anything about. But if you're not worried, I feel relieved as well."

Saying that, Marc opened the carriage door.

Inside, I found Erna waiting, looking distinctly displeased.

For a moment, actually running away crossed my mind, but I immediately gave up since I couldn't get away from Erna without using teleportation magic.

"...Marc. I have another problem."

"What is it?"

"Prepare to be surprised. My life is in danger."

"That's nothing unusual. If you nearly die, I'll save you again, so don't worry."

"There's something wrong with calling that 'nothing unusual'! Besides, if I die instantly, there won't be anything you can do!"

"Don't worry. She'll go easy on you."

With that, Marc pushed me from behind.

I couldn't even resist as he put me inside the carriage, leaving me alone with Erna.

"...H-hey..."

"..."

Erna remained silent.

She's definitely angry.

I knew why. It was because I'd told Silver about her weakness.

Under her fixed glare, I took a seat opposite Erna, feeling distinctly uncomfortable.

As far as I could tell, a soundproof barrier had been put up. It was the kind used for confidential conversations.

Just as I was thinking this was going to get into some serious matters, Erna opened her mouth.

"Is there something you want to say?"

"Hmm, are you hurt?"

"W-what!? Of course I'm not hurt! Who do you think I am!?"

Erna's face reddened faintly as she raised her voice.

Apparently, that wasn't what she'd expected to hear. Erna muttered in a small voice, "You're throwing me off..."

"You get hurt sometimes too, don't you? The odds may be lower than for an ordinary person, sure. Besides, it was obvious the sea would be the main battlefield this time. So I was worried. Maybe I was meddling, but I asked Silver to look after you. I'm sorry if that offended you. I shouldn't have done it. But who else would worry about you? You're my dear childhood friend, so let me worry about you, at least."

"...What... That's a low blow... If I get angry now, I'll look petty."

"No, you are petty. As if that's news."

"Al~? I might cut out that tongue of yours for saying unnecessary things~"

"Yes... I won't say anything unnecessary..."

Partially unsheathing the sword at her waist, Erna threatened me with a smile.

Her presence was as terrifying as a dragon's roar; anyone fainthearted enough to face Erna like this would probably faint, just as they would before a dragon's roar.

But while I was shaking in fear, Erna's expression somehow looked bright. When she'd gotten into the carriage, she'd worn a stern expression the entire time.

Now, she even looked to be in a good mood.

"Well, fine. I'll overlook the fact that you told that masked adventurer my weakness. But that's not what bothers me, you know? Do you understand what I mean?"

Saying that, Erna gazed straight at me.

Until just now, she had seemed almost sulky, to put it unkindly, but now it was different.

Faced with a gaze mingling concern and faint anger, I sighed.

"How much did Silver tell you?"

"He said that you and Silver are co-conspirators. You must trust him a great deal if you told him my weakness, right? What in the world are you two trying to do?"

"...Do I have to tell you?"

"Yes. If you don't, I won't let you out of the carriage."

"I see... Then I suppose I have no choice... Silver and I share the goal of making Leo emperor, and we're both working behind the scenes to achieve it."

"Working behind the scenes...?"

"That's right. The kind of behind-the-scenes maneuvering you hate. I use my position as a member of the imperial family, while he uses his position as an SS-class adventurer. Sometimes we even pretend things are coincidences to gain more allies. That's how we brought the Kleinert ducal family over to our side as well."

Erna knew that I was trying to make Leo emperor.

Of course, she also knew that I was vying for power with the other three.

But that was merely as Leo's aide.

She had never imagined that I was secretly connected to an SS-class adventurer and carrying out such schemes behind the scenes. She was at a loss for words.

"When the vampire incident happened in the east, I was in contact with Silver too. This time was no different. He's working for Leo's sake. But it would draw far too much attention if Leo and Silver were directly connected. That's where I come in—as their cover."

"...Does Leo know about this?"

"I've told him, more or less. But he doesn't know we're doing something as underhanded as this. Silver was in the south this time, too. Even so, he asked me to head to the imperial capital to give us an advantage in the succession struggle. He also had Fiene and the others contacted, preventing the other three from leading their armies. I prioritized the succession struggle, and as a result, many people died."

"...Is that really all for the sake of survival? Do you truly believe... that your older brothers and sisters would kill you and Leo?"

That was Erna's final confirmation.

I'd told Erna about it once before, but she must still have harbored doubts. I felt that she hadn't entirely believed me when I said I'd nearly been assassinated. She'd probably taken it as a threat.

At least, when Erna had been with us—in other words, when the Crown Prince was still alive—there had been no such atmosphere.

Erik had competed and trained alongside the Crown Prince, but he hadn't been the sort of brother who would consider killing someone, while Gordon had been a straightforward man of war. Zandra had been devoted to her training as a mage.

Yes, those had been peaceful days.

But when the Crown Prince died, the throne became vacant. The ambitions of the three, held down by the Crown Prince like a massive lid, had spilled out.

And as they fought over the throne for years, they lost their kindness.

I could say that with certainty.

"They will definitely kill Leo and me. And everyone around us, too... So I'll make Leo emperor by any means necessary. I told you at the festival, didn't I? Stay out of this. We're nearing dangerous territory. If you get any more involved with us, not only you but House Amusberg will be treated as our enemy. Are you okay with that?"

"...House Amusberg never gets involved in politics... That's what I've been taught since I was young. That we are the sword."

"Yes, wise. For better or worse, House Amusberg is far too powerful."

"But... I've made up my mind about something, Al. There's one thing I've always decided I will never yield on."

"What is it?"

Erna took a deep breath.

I had a feeling she was about to say something outrageous.

But I couldn't stop her.

I had never once been able to stop Erna, not since we were children.

"I will never abandon you, Al. I swore that as a child. I won't yield on this oath even if I had to face His Majesty the Emperor. If you're serious about putting Leo on the throne, I'll help you. If you're going to do whatever it takes, then so will I. If my family gets in the way, I'll even cast aside my family name. I will put my oath before anything else."

"You'd be disqualified as an Imperial Guard—and as heir to House Amusberg, too. Are you sure?"

"I'm stubborn. You know that well, don't you?"

"I do... Honestly, I'm grateful you'd help with that level of resolve. But keep a low profile for a while. If House Amusberg openly takes our side, we'll become the strongest faction. Then we could be hit with an all-out attack."

"I understand that much. I'll help without letting anyone find out."

"I don't think you're capable of that, though..."

"Don't underestimate me! I can do it properly!"

Saying that, Erna puffed out her chest.

Somehow, the sight was not reassuring.

But perhaps that was for the best.

Erna was a sword. Whether she saved or killed depended on the one wielding her—me.

"Yes! I feel so much better! Now that we've decided, let's do our best!"

"So for now, don't do your best..."

"What's wrong with getting fired up? Oh, right. Now that I'm officially your ally, no more secrets. There's nothing you're hiding from me, is there? If there is, tell me now. I'll let it go this time."

"Hmm... Oh, right. I gave you a pearl to celebrate becoming an Imperial Guard, remember?"

"Yes. You went all over the place searching for it, didn't you, Al?"

"Actually, it was too much trouble, so I had Leo buy it for me—cough!?"

"You absolute jerk!"

She punched me hard in the abdomen, and I writhed in agony inside the carriage.

But you said you'd forgive me...

The pain left me speechless.

Wincing through the pain, I was relieved that I'd somehow managed to hide the important part.

Somehow, I had avoided letting her discover that Silver and I were the same person, and the situation had also led to Erna giving us her full cooperation.

I'd gained a great deal here in the south.

With that thought in mind, I grew wary of what awaited me when I returned to the imperial capital.

Leo had accomplished something major this time.

He would probably receive a reward. If that happened, Father's view of him would change as well.

He would be seen as a fourth contender, standing alongside the three established powers.

If that happened, even Erik, who had never considered us much of a threat, would make his move.

The struggle for the throne was about to become even more fierce.

I could no longer afford carelessness like this.

I took the pain in my abdomen as a lesson and admonished myself.