“Mmm.” Hideo leans in to plant kisses along my neck, and I shiver. “A bounty hunter wandering the Dark World,” he murmurs. “Very appropriate.”

I close my eyes, my lips parted, and soak in the warmth of his arms wrapped around me, his kisses trailing along my damp skin. The rough scars of his knuckles brush past my waist as his hands pull me close. There is a shyness in his eyes now that makes him look so young, an expression that tugs my heart closer to him. I can’t remember when we start kissing or when we stop, or when he leans against me, made weak, whispering my name. We seem to exist in a fog of heat and dusk, and I don’t know where the time goes, but it seems that night falls in the blink of an eye, and soon the evening has swallowed us. We’re quiet now, leaning our heads against the stones lining the spring and watching the hanging lanterns illuminate the water with gold. Overhead, stars are winking one by one into existence—real stars, not a virtual simulation. It’s barely after dusk, but already I can see more stars than I’ve ever seen in my life, blanketing the sky in a sheet of light.

Hideo has his face turned up to the stars, too. “Sasuke was playing in the park,” he finally says, his words quiet in the empty space. I shift my head against the stones to hear him better. He seems thoughtful now, his mind somewhere far from here.

This is why we came here. This is the secret that weighs on him. I turn my head slightly toward him, waiting for him to continue. He seems to struggle in silence, wondering whether letting me into his world will be a huge mistake.

“What happened?” I whisper.

He sighs, closes his eyes for a moment, and then makes a subtle motion with one hand. A screen appears between us. Hideo is sharing one of his Memories with me.

I accept it without a word. In the next instant, the onsen and nightfall and view around us vanish, and both Hideo and I find ourselves standing at the edge of a park, surrounded by a golden, autumn afternoon, where the sun outlines the trees in a haze of light. A few auto-cars are parked along the sidewalk. Red and orange leaves drift lazily to the ground, dotting the green grass with warm color. A short distance from us, two young boys are heading into the park. I immediately recognize one of them as a young Hideo; the other must be his brother.

“You hadn’t invented the NeuroLink yet when this happened, did you?” I say as we watch the boys enter the park. “How did you create this Memory?”

“I remember every last detail about that day,” Hideo replies. “I was nine. Sasuke was seven.” He nods at the image of the brothers. “The park’s layout, the placement of every tree, the golden leaves, the temperature, the angle of the light . . . I remember it all as if it had happened only minutes ago. So I reconstructed this moment for myself as a Memory, in its entirety, adding new details to it every year.”

We now follow the point of view of young Hideo as he walks calmly, leaves crunching under his boots, his coat’s collar pulled up high against the chilly day. He’s yanking a bright blue scarf out of his backpack. Running a few feet in front of him is Sasuke—clearly the younger of the two—all grins and laughs, his boots crunching in the leaves as he sprints forward. When the boys speak, it is in Japanese.

“Yukkuri, Sasuke-kun!” the young Hideo shouts at his brother, waving the blue scarf in the air. I read the English translations in my view as he continues. “Slow down, Sasuke! Put on your scarf. Mom’s going to kill me if you don’t wear it.”

Sasuke ignores him. He’s carrying a basket full of plastic eggs, all colored blue. “Okay, this time you’re red,” he calls back at Hideo over his shoulder. “I’m blue. If I snatch all of yours before the sun hits that tree over there”—he pauses to point—“I get to have your favorite model car.”

Hideo rolls his eyes and lets out an annoyed sigh as they reached the park’s central clearing. “But it’s part of a set!” he argues, even though he doesn’t say no. He finally catches up to his brother. Despite Sasuke’s protests, Hideo forces him to stand still while he wraps the blue scarf around his brother’s neck and tugs his collar up higher. “We can’t stay out for long. Dad needs our help at the shop before dinner, and Mom needs to be at the lab until late.”

Sasuke pouts like a little brother would. “Fine,” he mutters.

The boys separate and head off to opposite ends of the park. As they go, Hideo pulls out a bag of plastic red eggs from his backpack. They both start tossing them all over the place, each one taking great pains to hide them properly from the other.

A blue egg comes tumbling into view, and Hideo looks up to see Sasuke wearing a goofy grin. “Threw it too hard!” he shouts. “Can you toss it back?”

Hideo grabs the egg and flings it back at his brother. The egg flies far past the clearing and disappears into the thick of the park’s trees, where they line the banks of a tiny stream overgrown with bamboo. He laughs as Sasuke’s grin changes into an exasperated frown. “Wait for me, Hideo,” he calls over his shoulder, and then he stomps off into the trees to fetch the egg. Hideo turns his back and keeps setting out the other eggs. A few minutes later, he glances over his shoulder.

“Are you done yet?” he calls out.

No answer.

Hideo stands up straight and stretches, savoring the warm glow of the afternoon sun. “Sasuke!” he calls again at the thicket of trees. The only sounds that answer him are the faint trickle of the stream’s water and the hush of golden leaves drifting in the air. The breeze whispers through the swaying bamboo stalks.

A few seconds pass before Hideo lets out a sigh and starts trudging over to his brother’s end of the park. “Come on. We don’t have all day,” he says. “Sasuke! Hurry up!” I look on as we follow him through the trees and into the overgrown grasses, slowing occasionally whenever the foliage turns too thick.

“Sasuke?” Hideo calls again. His voice sounds different now—the exasperation gone, replaced with a twinge of confusion. He stops in the middle of the trees, looking all around him as if unable to believe that there was another person who had just been here. Long minutes drag by as he does an exhaustive hunt of the small thicket. He calls again. Now there is a note of concern. Then, fear. No sign of another boy. It’s as if he had simply ceased to exist.

“Sasuke?” Hideo’s voice becomes urgent, frantic. His steps quicken into a run. He hurries out of the thicket and back into the clearing, hoping that his brother had somehow wandered back there without hearing him. But the rest of the park stays empty, the boys’ blue and red plastic eggs still scattered all over the grass, waiting for the game to start.

Hideo halts in the middle of the clearing. The Memory turns panicked now, the world blurring around us as Hideo spins in place, looking one way, then the other, then running to another section of the park. The view shakes wildly as he goes. His breaths come in short gasps, sending clouds of mist up in the chilly air. When I catch a glimpse of his face reflected against the metal of a parked car, his eyes are wide and dark, the pupils dilated with terror. “Sasuke! Sasuke!” Each shout sounds more like a scream than the last. Hideo calls and calls until his voice begins to crack.

He stops abruptly, gasping for air, and clutches his head with his hands. “Calm down. Sasuke went home,” he whispers. He nods to himself, believing it. “He went home early without telling me. That’s where he is.” Without another hesitation, he starts running home, scanning the sidewalks wildly, looking for the back of a small boy wearing a bright blue scarf. “Please, please,” I realize he’s whispering to himself as he goes. The word trails out in a repeated line, thin as a ghost.

He doesn’t stop running until he reaches his home, a house I now recognize. He pounds on the door until his father opens it, his face bewildered. “Hideo—what are you doing here?” He cranes his neck and looks behind Hideo at the sidewalk. “Where’s your brother?”

At the question, Hideo seems to waver in place, and I can see that, in this instant, he knows his brother never came home, he knows something terrible has happened. Behind him, the sun has already started to set, washing the landscape from gold into pink.

All I can think is that it is far too beautiful of a day.

The Memory ends. I’m startled as the onsen reappears around me and Hideo, the peaceful fog of hot water and the glisten of early lamplight on the rocks. I look at him. He doesn’t say anything; he doesn’t look at me. He doesn’t even seem to be here anymore, for the look on his face is distant and grim. Afraid. After a pause, he brings up another Memory. It is the same sequence we just watched—except he has altered the park’s landscape, shifting the stream a little this way, a little that. He brings up a third Memory. Same sequence, but with the brothers in slightly different positions.

“I can’t tell you how many times I’ve gone over this scene in my head,” he finally says to me in a soft voice. He flips to another, and yet another, each with subtle details changed. This time, the scene shows Hideo turning around a few seconds sooner and calling Sasuke back before he can go into the trees. Another one shows Hideo steering Sasuke out of the park and back home before they can start playing their game. Yet another shows Hideo going with Sasuke to retrieve the plastic egg instead of leaving him to do it himself. My heart cracks a little with each new variation. This is his endless hell. “I can remember every single detail about that day . . . except the details that matter. Where he went. When I stopped hearing his footsteps in the leaves. Who took him. I think about what might have happened if I’d done this. Or that. If things had shifted even a little.” He shakes his head. His jaw is so tight that I’m afraid he might break it. “I don’t know. So I keep building.”