Interlude
KAZUNE SAID it would take ten years of work to arrange everything I needed to make time travel a reality. Sure enough, precisely ten years later, we finished the modifications on our equipment. From there, we performed dozens of experiments until I was confident that all would go exactly to plan.
There was just one problem left, however. Which world?
The Schwarzschild IP, or SIP, was the radius within which a given event was guaranteed to take place across all worlds. The SIP of Shiori meeting me was a perfect match with the SIP of Shiori suffering imaginary karyomitosis. In every world where we met, she would always die at the intersection and become a ghost. So the world I needed to merge with had to be a world where we never, ever met.
And so I began to shift through all the different worlds, searching for one where we never knew each other…but as I would soon realize, that wasn’t enough.
✦ ✦ ✦
“We need a way to predict the future.”
That was the first thing I said after I got back from an optional shift.
Kazune furrowed her brow at me. “Excuse me?”
“Think it’s possible?”
“In theory, yes. Maybe if we input a world’s worth of data into a quantum computer or something.”
“Okay, you do that.”
“Are you out of your mind? You know I can’t!” she scoffed in exasperation as she helped me out of the IP capsule. “Where did this come from all of a sudden?”
“I’ve realized this method won’t work.”
“Why not? Surely there must be one world where the two of you haven’t met.”
Rest assured, there were plenty of those. However.
“Take the world I just visited, for instance. I can confirm that Shiori and I haven’t met in that one. I was working at the ISRI. But then…” The memory gave me pause, and I let out a sigh.
“Then what?” Kazune pressed when she noticed I’d stopped. I took a sip of tea to wet my whistle, then forced myself to continue.
“Someone’s wife and daughter walked in to bring a basket of snacks for the team. Apparently they hadn’t met me before, because they said ‘Nice to meet you,’ and…”
“…And? What about it?”
She didn’t seem to get it. I didn’t either, at first.
“I’m saying that even at our age, there’s always a chance we’ll meet someone new.”
At that, she paused for a moment…and then her eyes widened as she realized what I was saying. Finding a world where Shiori and I were guaranteed never to meet was singularly close to impossible.
For instance, at age fifty in my world, my parallel self would also be fifty. And there were infinite parallel worlds out there, with plenty of worlds where Shiori and I hadn’t met within those fifty years. One might think this meant I could take my pick of them. But no, that wasn’t good enough.
Suppose I chose one of those worlds where Shiori and I hadn’t met within fifty years, went back in time, and merged with it. What if we met the very next year after that? It was impossible to deny the possibility.
At this point, I couldn’t allow myself to meet Shiori at any age. The moment we met, it would ruin her life. That was the inalienable truth of my world.
“I see… So we need to predict the future,” Kazune muttered wearily.
Without a way to know the future, there was no telling which of these worlds would keep me and Shiori apart our whole lives.
“Well, what now? Do we give up?”
Of course, giving up was not an option. Not after how far we’d come.
“I’ll figure it out.”
And so I threw myself back into the IP capsule…in search of a method I wasn’t sure I could even find.
✦ ✦ ✦
The parallel world I visited that day was one where I’d seemingly chosen to live with my mother after my parents’ divorce. Reminiscing, I stepped out into the backyard to find a small mound of raised earth off in one corner. Yuno’s grave.
After fifty years, I didn’t expect it to still be there. I pressed a hand to the earth and found it cold. I couldn’t remember Yuno’s warmth anymore.
Then I thought back to what Shiori had taught me. As long as Yuno was warm, you could play with her, pet her, talk to her—all kinds of possibilities. But when she died, she went cold. Without that warmth, her world and all its possibilities came to an end…
The next instant, a jolt of electricity shot through my entire body. I rushed back to my home world, and the instant Kazune opened the glass door, I started babbling without even waiting to get out of the capsule first.
“I got it! I worked out how to find a world where she and I never meet!”
Startled, Kazune patted me on the shoulder, urging me to calm down. Then she made me some tea. But even that wasn’t enough to quell my excitement.
“Listen to me, Kazune. I’ve got it all figured out this time!”
“Yes, yes, I’m all ears. What’s your solution?”
“First, we find a handful of candidate worlds. Then we monitor them over the course of a few years. Maybe decades.”
“Maybe decades? Why?”
To minimize the possibilities. To wait for the warmth of possibility to go cold. In short, I meant… “However long it takes for my life to start running out.”
She stared back in silent shock.
“Whether it’s a disease, an accident, or natural causes, we have to wait until I’m on my deathbed without having met Shiori. Any world that makes it that far gets my stamp of approval. If I travel backwards in that world’s time, then fuse with it, I’ll die without ever meeting her. And if, worst-case scenario, we somehow meet at the last second…well, I probably won’t ruin her life, right? Since I’ll be dying soon after.”
I rambled endlessly without even gauging Kazune’s reaction. Did my reasoning make sense? Was it coherent? Evidently, I had lost the rationality to decide these things for myself. Was my age creeping up on me, or was I a special breed of crazy? I wasn’t sure anymore.
“Well, what do you think?” I asked. “Could this—”
Only then did I finally look at her face and realize that she was looking at me with deep sympathy in her eyes. What? Why is she looking at me like that? Isn’t it the perfect plan?
“Look, Kazune, we’ve got another long road ahead of us, but…will you join me?”
She was the only person I could ask now, so if she said no, I was up a creek. Then she looked down at the floor and said, “It’s a little late to abandon you now, you dolt.”