I read once—somewhere between a dentist’s waiting room and a cereal box article pretending to be science—that solid objects aren’t solid at all.

Atoms, it said, are mostly empty space. The nucleus is tiny. The electrons are distant. Everything else is force and agreement. We don’t pass through walls not because they’re full, but because the universe politely but firmly refuses to let the rules bend.

That thought stuck with me. It shouldn’t have, but it did. Every time my hand hit a table, every time my shoulder caught a doorframe, I thought about all that empty space stopping me cold.

My body, meanwhile, had its own opinions about boundaries.

I’d had the mucus problem all my life. Thick, stubborn, pooling at the back of the throat where the sinuses drain. Not a cold. Not allergies. Just a constant presence, like my body never trusted air to behave itself. I cleared my throat more than I spoke. Swallowed more than I breathed.

Doctors shrugged. “Post-nasal drip,” they said, which is a phrase that explains nothing while sounding authoritative.

Most of the time, it was just annoying.

That night, it wasn’t.

Pressure built behind my face without warning. No itch. No tickle. No buildup. Just a sudden, overwhelming certainty that something was about to happen.

The sneeze hit like an explosion.

Not polite. Not singular. A full-body convulsion that folded me in half and left warmth everywhere it shouldn’t be. Mucus—far more than should exist—coated my arms, my chest, my face. It stretched, slid, clung. My eyes burned. My throat locked.

I staggered backward, trying to orient myself.

My heel caught the edge of the bed.

I fell.

The mattress didn’t stop me.

The fabric gave without resistance, the springs passed through me like suggestions, and then the floor vanished. I dropped straight down, clean and vertical, through beams, wiring, and joists that offered no objection at all.

I landed hard in the basement dirt, coughing, gasping, mucus dripping off me in slow, stringy arcs. Above me, the ceiling was intact. Untouched. As if I’d never passed through it.

That’s how I learned the rule.

It didn’t happen all the time. It didn’t happen just because I was wet or slick or miserable. It happened only after those sneezes—the sudden ones, the ambushes, the kind that came out of nowhere and left my body convinced it had lost a fundamental argument with reality.

As long as enough mucus stayed on me, solidity became optional.

Each boundary crossing stripped a little away. Walls wiped me clean in places. Floors took more. Gravity did the rest. Once the coating thinned enough, the world remembered how to hold me.

Weeks later, walking across the tile floor toward the office of the rhinofibro-physician—someone who had invented his own specialty and charged accordingly—it happened again.

No warning.

One violent sneeze.

And then the floor was gone.

I fell through an office ceiling, past fluorescent lights, and into a space tiled in pale blue. The air smelled of disinfectant and something human underneath it. For half a second, gravity slowed just enough for me to register sinks, mirrors, stall doors.

A woman looked up.

Not screaming. Not yet. Just confusion, followed immediately by horror, as I passed straight through the space where I absolutely did not belong.

I tried to apologize. I couldn’t. My mouth was full of mucus and motion, and then the floor took me again.

Twelve stories later, I stopped.

There was barely enough left on me to keep from sticking halfway through the concrete.

Home became a negotiation. Furniture couldn’t be trusted. Sleep required vigilance. A single uncontrolled sneeze could send me slipping through foundations into places not meant to contain people.

The body kept producing mucus. Not as a response to danger—but as danger. A system designed to protect deciding, again and again, that the world itself was too abrasive to touch.

The dog found me one night after a bad episode.

Old. Patient. Dumb in the kindest way. He sniffed, then got to work, licking methodically. Salt, apparently, was worth the effort. He cleaned me the only way that mattered.

When he was done, I was solid again.

Not cured. Just… contained.

The mucus would come back. Another sneeze would come eventually. I knew that now. The body doesn’t abandon its habits. It only pauses them.

The dog curled up beside me, satisfied.

Atoms are mostly empty space, but that doesn’t mean we get to pass through things.

Sometimes the universe enforces boundaries.

Sometimes the body does.

And sometimes, if you’re lucky, something warm and unthinking holds you in place long enough to rest.