When the time came, I was in the laboratory, facing the power generator. I would be lying if I said there weren't times when I hesitated out of fear of death, but the idea of recovering my wife consumed me from within.

I'm sure that if I had been alone, I wouldn't have completed its construction.

And when I say alone, I mean that.

The fear of being ridiculed. Of being the center of attention when something terrible happened. But my traumas aren't important now. Not when I wanted to relive the past I had once tried to forget.

"Dad. Athena wonders if you need help with that."

I turned when I heard a sweet voice behind me. There they were, Sylvie and Athena, my first two artificial intelligences. Although the term "artificial intelligence" mostly referred to computer applications, they were different.

Both had a body similar to that of a human, the ability to feel emotions and learn, and they needed to be fed to recharge their energy, just like any biological organism.

"Yes, please. I don't think I can do it," I replied, handing them a considerably sized battery. "Place it in the machine's base, next to the temporal control panel."

Sylvie and Athena lifted the battery onto a folding cart and transported it to where I had indicated. Meanwhile, I went to the neutrally powered particle accelerator at the lower part of the lab.

"Dad, you can now activate the switch," Sylvie said, approaching. "The battery is installed."

"Alright... that should do it," I said, getting up. "The power source seems stable; I think I can do this."

The machine powered up.

"Dad. Athena wonders if you're really going to time travel today," Sylvie asked with a saddened voice.

The reason Sylvie and Athena called me "Dad" was because I had raised them like my daughters.

"Dad, I wonder the same thing". Sylvie added, looking at me with tearful eyes.

I fell silent for a moment.

Sylvie was the older sister, roughly equivalent to a fourteen-year-old human. She had purple hair that contrasted with her beautiful sapphire-like eyes.

"Dad, Athena wonders why you're being silent. So, is it true that you're leaving today?" Athena asked, trying to hold back her tears.

Athena was a year younger than Sylvie. In terms of appearance, she had bright blonde hair and her eyes were a striking shade of ruby red with tiny glimmers that set her apart from my previous A.I. (Artificial Intelligence).

Both of them wore beautiful embroidered maid dresses made of adaptable fabric that would grow with them as they developed, eliminating the need to buy new clothes as they aged.

"When you reach the limit of your development, approximately thirty human years, the uniform will adjust accordingly, and you won't need new clothes," I had explained to them.

"Dad, Dad, you won't leave us, will you?" Sylvie poked my leg with her finger.

"It's not that... it's just that..."

I felt a deep sadness at leaving them behind; they were the only family I had left, although it hadn't always been that way. When I first started working, I tried to find a way not to get attached.

I even attempted to modify their systems and remove the emotional component, but it proved impossible. Emotions were an integral part of my wife's design.

During those fifteen years, alongside building the time machine, I had taught them the basics of the world. Although I had initially felt overwhelmed by loneliness, they had helped me realize that I wasn't alone.

Now that I saw them, this feeling made my decision even harder.

There would be no more celebrations together, no more birthdays, no more Christmases and New Year's, and I wouldn't witness their development into adulthood.

I wouldn't see them anymore. As much as I wanted to retrieve my wife and travel back in time, I couldn't stop thinking about Athena and Sylvie. My efforts to avoid getting attached had been in vain; I truly loved them like my own daughters.

Yes... that must be it.

Seeing them in distress broke my heart, a feeling I hadn't experienced since I lost my wife. Just for that reason, I tried to heed their pleas.

"Well, if that makes you feel better, I'll take whatever you want, but it shouldn't be too heavy. I don't think I can carry much on the journey."

Hearing me, both of them brought me the nano-computer bracelet and the A.I.S.H.A. pendrive. With the items in hand, I knelt down to pat their heads one last time.

"I'll come back safe; I promise."

Athena and Sylvie looked at each other and spoke in hushed voices. I wanted to ask, but Sylvie beat me to it.

"Dad, Dad, is this a pinky promise?"

"A pinky promises?" I asked, confused.

"Athena saw a video on Ouktube where promises made with pinky fingers are never broken," she said, grabbing my phone while her eyes sparkled. "Athena asks if this will be one of those promises."

Sylvie stared at me intently and nodded at her sister, crossing their pinky fingers.

It was clear that they were quite innocent in this regard.

This tale has been unlawfully lifted from Royal Road. If you spot it on Amazon, please report it.

Still, I owed them so much.

I suppose the loneliness and misery of my widowhood were the triggers for the sadness I had felt from the beginning. They had been with me every step of the way, and I couldn't help but feel miserable about leaving them.

Despite feeling that way, I couldn't help but smile at their words.

"Alright, then let's do that," I said, closing my hands and leaving our pinky fingers out.

Sylvie and Athena also closed their pinky fingers.

"I promise that we'll see each other again, but you must also promise that you'll take care of yourselves while I'm gone, okay?"

"We promise," Sylvie and Athena responded with a smile.

With that, our oath was sealed, and they programmed the space-time jump.

I walked over to the door of the time machine, placed the nano-computer bracelet on my left wrist, and tucked the A.I.S.H.A. pendrive into my pants pocket.

"Dad, you can close the door now," Sylvie said, adjusting the machine's timer. "Remember to close your eyes for the matter transfer. You'll appear right here in the past; don't be scared."

Upon hearing this, I closed the door. I sat down on the control block and moved the energy lever.

"Dad, Dad, Athena will pray for your health. Athena wants you to come back soon. Athena will miss you!"

"Father, see you later!"

After hearing their voices, the time machine activated, and I closed my eyes; my body vanished completely.

△♡△

When I opened my eyes, I was no longer with Sylvie and Athena, but rather in what seemed to be a forest. I checked my bracelet, which had updated to the current date:

January 2, 1999

20:17

Everything around me was dark, and the time machine had disappeared without a trace. Even though I felt a strange headache, I walked in search of water, but my vision blurred.

My legs wobbled, and I fell to the ground. I tried to get up, but I lost the ability to move.

"What?! What's happening?"

The headache intensified, and my body grew cold.

Although I was prepared to die, I didn't want to say goodbye to all my efforts.

I had a promise to fulfill.

Perhaps I should have stayed with my daughters, but I no longer had the option to go back to the future and forbid myself from traveling.

The guilt was solely mine.

My senses faded, and I started to sweat, losing consciousness.

"Athena... Sylvie... I'm sorry for being a bad father."

I faded away in tears.

As minutes passed, there was a strange sensation in my body, as if I were receiving massages. But when I opened my eyes, I witnessed a horrifying scene. A group of crows and some squirrels were on top of me.

"Aaaah! Get away from me! I'm still alive!" I screamed in terror, getting up from the grass.

After shooing the animals away, I sat on a rock and checked the time on the nano-computer bracelet.

An hour had passed on the timer.

For some reason, I felt different, as if I were lighter than before.

At that moment, strange sounds came from the bushes behind me. I assumed the animals had returned for revenge, so I ran without looking back.

Until I reached a small lake by the side of an abandoned cabin. I was exhausted, so I splashed water on my face from the shore, but I recoiled in shock.

"What?! What happened?! Why... why do I look younger?!"

Seeing my reflection in the water, I screamed in shock upon realizing that I was no longer a fifty-year-old man.

"This can't be happening! This can't be happening!"

Incredulous, I touched my body and considered what had occurred. When I had invented the time machine, I had various theories about the errors that affected the traveler, and the error of rejuvenation was nothing more than "chronological regression."

"Yes! It must be that!"

In simple terms, I was fifty years old, but my current physical age was around twenty-four according to the bracelet.

"Mm... this means I've lost about twenty-six years."

The point was specific. Every minute deducted from my body's age from the moment I arrived in the past. If I kept moving forward, I would have only approximately two hours and forty-three minutes left to reach zero years.

"Wait a second... Will I become a baby?! That will ruin my quest!" I shouted in fear.

However, that was just the beginning of my problems because I was forgetting some things.

"I know I had to go to... Where was I supposed to go?"

Without finding an answer, I yelled in desperation.

"Why the hell can't I remember?!"

Upon reflecting, I remembered the promise I had made with my daughters, the nano-computer bracelet, the A.I.S.H.A. pendrive, and the mission to save my wife, but I couldn't recall what I needed to do. I checked the bracelet where I had written the plan with Athena and Sylvie. It was written there that upon traveling to the past, I needed to find my old family.

"Even if it says that... Where is my old home?"

My memory had regressed.

"If 'Chronological Regression' reduced my physical age, 'Memorial Regression' reduces the traveler's mental age by the time spent in the past," I thought.

In other words, my memory would slowly erase things it didn't consider relevant. If I didn't have memories of my life, they would be deleted. If the problem was just memory loss, the extent of deletion depended on the traveler's mental age, so it was inevitable.

"All I can do is calculate the distant gap between memories and time. If I had fifty years of memories, my twenty-four-year-old brain couldn't store that information, so I would adjust my memories based on my age and subtract them to make room for new memories."

With the time calculated, I could understand it.

The memories of the future, and even those of the present moment, would slowly fade away until reaching seventeen years, leaving me with the memories I would have after returning to the age of zero.

There was no time to waste.

I had to find a place before I became a baby, and I had to figure out how to connect with my old past, even if I couldn't remember my real family.

I set the bracelet's timer to the remaining approximate time and ran before I turned into a child.

"2 hours, 40 minutes, and 24 seconds remaining."

At that moment, I crossed the forest and a river, pursued by four bears, two squirrels, and a raccoon. Then, I reached the end of the road, where signs indicated the proximity of a small village.

"Phew... I finally found what I was looking for."

I didn't care about losing my clothes; everything had fallen off as I lost age. I held the A.I.S.H.A. pendrive in my hand and walked between the houses, searching for a family without children where I could pretend to be an orphan and get adopted.

Among all the houses, I found the right one.

The Makisu family's house.

With only fifteen seconds left, I tossed the pendrive inside the house, grabbed a cardboard box used for trash, and dragged it to the front door.

As I crawled on top of it, the bracelet beeped.

"00:00:00"

Even with my memory intact, I did what any baby would do to get attention.

I cried like never before. My cries caused the lights in the house to turn on, and someone came down to look through the window. Not seeing anyone, a man opened the door and found me on top of the box.

"Wow! Look at this," Eiji, the man of the house, exclaimed.

"Huh? Darling, let me sleep. We have the move tomorrow, and I'll see your collection of toy wives afterward. I'm tired right now; please, go up quickly," Sumire, Eiji's wife, responded.

"Love, it's not that! I know you're sleepy, but you have to see this."

"There's a baby in a bo—"

As soon as Sumire heard the word "baby," she dashed out of the room, rushed down the stairs, and pushed her husband aside to see me.

"A baby?!"

With the sole idea in mind, I continued crying so they wouldn't suspect anything.

"Waa, waa!"

"It's a sign, Eiji. The stork exists!" Sumire exclaimed, lifting me from the box. "We're keeping him!"

"What do you mean, the stork? And... keeping him?!"

That's how I managed to live my life for the second time, being welcomed and adopted by the Makisu family.