I sunk to a sitting position, knees at my chin, back against the fake wood-paneling. Why do you always, always drink too much? Idiot. I tried to focus on the feel of the carpet under my butt, the smoothness of the wall at my back. I tried not to think about my stomach.

Please, please hurry back.

Something changed around me, subtle but significant. Head swimming, I couldn’t lock on to what, at first, was different. I blinked, squinted.

The light. The play of light around me had changed, gone darker, even though none of the wall sconces in my field of vision had gone out or gotten any dimmer.

We were at a T-junction, where the hall we’d come from, back to the big room with the fireplaces, had branched in two directions. I was slumped against the wall facing the way we’d come, head turned towards the right-hand fork, the way Niko had gone.

I decided the sudden dimness must be from the lights in the hall behind me, the one we hadn’t explored yet. They must have gone out.

Carefully, still fighting nausea, I turned my head.

I’ve always had an unhealthy imagination. This has manifested itself in various ways over the course of my life. Staying under the covers reading comics instead of doing homework, or sleeping. Satisfying myself with vivid fantasies about guys I crushed on rather than risk asking them out in real life. Obsessions, where each new hobby would become all I could think about. Things get lodged in my head and they stay there, sometimes for too long.

The other hall was dark. The lights were off, and the dark brown walls sucked up the refracted light from the other two hallways, so that the end of this one, where it turned another corner, was right at the edge of shadow.

But there was enough light to see that someone was standing there.

In sixth grade I had a brief friendship with a weird, indrawn kid with the same unhealthy imagination as me. He liked to possible. When you catch something from the corner of your eye, he’d explained, and it looks for an instant like something fantastic—a witch’s face in a hedge, a huge monstrous far-off thing instead of a tiny nearby insect—instead of correcting your perceptions, you let yourself keep believing in that first impression for as long as you can. You possible it. Hold it in your head, your mental model of what’s real. Keep your mind from asserting the boring truth it thinks it knows and trust the one your senses first perceived. And I’d tried this, with him and on my own, off and on for a few weeks until I scared myself because I was getting too good at it. So was he: I realized it before long when he started scaring me with stories about the things he’d seen, and I think his parents or the school figured it out not long after, because they took him away and I got sent to a counselor for a few weeks just for being friends with him.

But you don’t unlearn something like that. Not completely.

I stared at the person lost in shadows at the end of the hall and tried to unsee them, to resolve them into a trick of angles and darkness: turn off my brain’s over-eager pattern matchers, finding predators in a coincidence of edges. And at the same time, I could feel that old part of me fighting this, trying to keep seeing what it thought it saw the first time.

A person, standing there in the dark. Watching me.

It didn’t help that the hallway was spinning and I felt closer and closer to throwing up each second.

It moved.

The shadow took a step forward, slow and deliberate. Like a deer not sure if it’s seeing a bobcat or a bush. I couldn’t see its eyes or expression but it was facing me, looking at me.

And then I realized who it was.

Whether my eyes had started adjusting to the dim light, or the possible in my brain was shifting into high gear, I couldn’t say, but like the solution to a puzzle plunking full-formed into my head I recognized, now, who was standing there at the end of the hall.

It was me.

I clutched the carpet under my hand, feeling for the solidness of it, an anchor back to reality. Everything was spinning. My stomach churned and my mouth filled with saliva, like the glands for adrenalin and poison protection were crossing wires. Fight, flight, or puke.

The face was still dark but I recognized the way the body held itself, the silhouette it made, the shoes. Unmistakable. The person in the mirror, except I’d never seen him from this far away before.

I squinted into the darkness, seeing something else now. Something barely visible, even further back in the shadows.

There was more than one of them.

The second stood just behind the first, so I couldn’t see its face either: but it was the same silhouette, the same height, the same shape. It was another one, identical. Another me. It had been there all along, perfectly hidden behind the first, and I could only see it now because they were moving again, lifting up the other foot, just as slowly, hesitant, following the double in almost perfect synchronicity. Like they were glued together.

They put the feet down, gentle, soundless on the thick carpet.

Another pace closer.

Seeing double. You’re drunk. Except I’d never had it happen in three dimensions before, along the z-plane. And the edges of the hall weren’t doubled at all.

I wondered how many more were stacked up behind them. How many more I couldn’t see, each pressed up against the last, a line vanishing into the darkness, stretching back god knows how far, waiting patiently for something I could never understand.

I wondered what they wanted.

I wondered how fast they could reach me if they started to run.

“What you looking at?” Niko asked from behind me, and I leapt, fucking leapt to my feet like the floor was electric, whirling around to face him, body in full panic like all the building adrenalin had been released in an instant and I guess it probably had; panting and overwhelmed with terror and nausea and a terrible, stabbing relief at seeing him, seeing a him I could believe in instead of a me I couldn’t.

“The lights back there went out,” I said, gasping, not looking behind me. Also, more certain: “I need to throw up.”

He clapped my shoulder, grim. “Let’s get you back upstairs.”

I let him shepherd me away. I didn’t look back down the hall.

But as we left, his arm protective on my shoulders, he frowned. “Pretty sure those lights were out when we first came down here, man.”

This is just one way the story can go. In the final version of Subcutanean, the text will change for each new reader: no two copies will ever be quite the same. Find out more at https://igg.me/at/subcutanean