The rain made the dormitory sound hollow, as if the building had been scooped out and set back down with nothing inside it but echoes. North Hall's fourth floor stuttered with dying fluorescents, a vending machine hummed like a tired throat, and somewhere a radiator clanged three patient notes before giving up. Ethan Walker had a statistics book open on his lap and a pen in his hand because doing normal things was how you told the night you weren't afraid of it.
Ben, his roommate, had passed out on his back with one earbud still in and a playlist of heroic movie themes trying to pep-talk his dreams. Liam sat in the opposite bed like a king who'd abdicated, shoulders propped on pillows, phone glow whitening his face. Liam had the grin of a person who always had a plan and, occasionally, a reason.
"Listen," he said without looking up. "There's a thread—Dorm Room Rules, Verified. The guy who posted is local."
Ethan turned a page without reading it. "Local as in campus? Or local as in lives under our beds?"
"Campus." Liam scrolled, the blue on his face flickering. "Rule one: If there's a knock at your door at exactly midnight, do not open it."
"Revolutionary," Ethan said. "We've invented the concept of not letting strangers in."
"Rule two," Liam went on, pleased, "If the knock happens three times, wait sixty seconds and ask, 'Who is it?' If it answers in your voice…"
"Please stop," Ethan said, but his mouth had gone dry. They'd all seen the stories floating around—bus routes that didn't lead anywhere buses should go, elevators that stopped between floors and opened on rooms that shouldn't exist. They were the kind of rumors you laughed at in daylight and carefully did not test after dark.
Ben snored, rolled over, punched his pillow, and announced to the room, "Five more minutes," like time was his employee.
The window sweated. Wind slipped under their door, flipping the corner of a takeout menu the way a bored hand might flip a playing card. The clock on Ben's desk ticked even though it wasn't built to tick. 11:57 p.m.
"Rule three," Liam said, softer. "If you slide a mirror under the door and the reflection doesn't blink when you do, wait until two a.m. If the knock continues after two… move."
"Move rooms?" Ethan said.
"Move out," Liam said. "Of the building. City. Country, if you can swing it."
Ethan closed his book. He didn't like how the rain had started to sound like whispering. "You know you're just feeding yourself nightmares."
Liam lifted an eyebrow. "If I'm hungry enough, I'll eat sleep too."
The clock coughed over to 11:59. Ethan said, to no one, to the night, "It's fine. No one is out in this rain. The worst thing that happens is the vending machine finally kills itself."
Liam's grin stretched. "You cursed it."
Midnight arrived like a held breath released, and then somebody knocked.
The sound was polite—three taps of knuckles, measured and neat. Not the aggressive pound of a drunk friend, not the scamper of a prankster. It was the knock of an old-fashioned postman: I'm here; you know what to do.
Ben's snore snagged and stopped. Liam's grin vanished as if pulled off with a cloth. Ethan felt every sensible thing he'd ever thought try to get out of his body at once. "Coincidence," he said, because even fear appreciated narration.
They waited. The building listened to itself. The knock did not come again.
"See?" Ethan said, and his voice wasn't steady enough to carry the point. "Probably someone got the wrong door."
His phone buzzed. Unknown number. The preview hid itself like it was shy. He opened it anyway.
Is Ben there?
He looked up. Ben was drooling into his pillow. Liam's eyes had gone very focused and very empty, like he was looking at something far away that only he could see.
"Wrong number," Ethan typed, and added a thumbs-up because panic turned him into a customer-service representative.
The dots blinked. Stopped. Blinked again. No message arrived.
At 12:01, the knock returned. Three taps, patient. As if the first set had been a question and this was the reminder.
Liam slid off his bed and onto his feet without a sound. "Sixty seconds," he whispered. "Like it said."
"Like what said," Ethan said, though he knew perfectly well.
"We ask who it is," Liam said. "But we do not open."
"We don't open," Ethan agreed. His mouth didn't believe him.
Liam's hand went to the desk drawer and came out with a small black hand mirror, the cheap lacquer kind with a cracked handle. "Prop from an ex," he said. "Useful for fixing hair and not dying."
Ethan almost laughed. He didn't, because the knock came a third time, softer, as if whoever stood there had leaned their forehead against the wood so it could feel the room breathe.
Ethan stepped close. The peephole was a cheap fisheye. Last week they'd taped over it when Liam had woken convinced something had been looking back through it. The tape was still there, dull and undisturbed.
"Who is it?" Ethan asked, pitching his voice low so he wouldn't wake Ben. He hated that he asked. He hated the part of him that wanted to be polite to whatever had chosen to be polite to them.
"Ethan," said the voice outside.
It was his voice, not a recording. He heard the particular drag of his own vowels, the little scrape when he said th as if his tongue didn't quite trust the world enough to give it that sound freely. The intimacy of it made him feel skinned.
Liam's mouth formed no.
"What do you want?" Ethan said, because if he stopped talking he'd have to hear his heartbeat, and his heartbeat sounded like knocking from inside his ribs.
"Open the door," his voice said. Pleasant. Reasonable. Patient.
Liam crouched and slid the mirror flat to the seam under the door. "If it's you," he whispered, "you blink."
The hallway lights night-cycled low at midnight. The gap under the door admitted almost nothing. For a second the mirror was only a rectangle of deeper dark reflecting the underside of the world.
Then it fogged.
Not with steam. With the shape of a breath where no mouth should be. The fog rounded at the top as if pressed by the tip of a nose. A fingertip smudged a vertical line through the condensation. Stopped. Drew a crossing stroke.
"A cross," Ethan whispered, and then, immediately, "Two lines. It's two lines. It could be anything."
Pressure built on the mirror from the hall side—no weight, exactly, more like intention. The glass scraped an inch into the room. Liam snatched it back with a hiss like it had burned him. On their side, the glass was ice-cold. Their faces wobbled in it, wrong by a fraction, as if the reflection had been taught their features by rumor.
The knock didn't come again. The room pretended it was normal.
Ben sat up so fast his earbud yanked free. "If this is a late-night Among Us bit, I'm voting both of you off."
"Don't open the door," Ethan said, and sounded like the kind of person who survives horror movies by never convincing anyone of anything.
"We're not opening the door," Ben said, offended. "But also… what the hell."
A faint dragging sound started in the hall—fabric on tile. It moved past their door, paused, returned, paused again, like a pendulum learning a new rhythm. The building turned into a lung. They were a clog in it.
Ben stood. "If it's some creep, we tell them to go creep somewhere else," he said. "If it's not a creep, we—what?—call campus exorcism?"
"Do not open the door," Liam said. The words were too mild for how much iron he put in them.
Ethan's phone buzzed again.
It's cold out here, Ethan.
Please open the door.
Ben reached for the chain latch.
Liam caught his wrist. "Don't."
"Look," Ben said, halfway to brave, halfway to stupid, which was brave's secret name, "if someone knows our names and they're going door to door, they'll keep knocking until someone opens. Better us than… I don't know. That kid at the end of the hall who cries on Thursdays."
"That kid cries on Tuesdays," Ethan said reflexively. "And he's on a journey."
Ben set his jaw. "We can't hide forever."
"Nobody is suggesting forever," Liam said. "I'm suggesting two a.m."
Ben unhooked the chain and thumbed the deadbolt.
The hallway lights went out.
They didn't flicker. They cut, deliberate as a hand on a switch. The gap under the door went from dim gray to a black so dense it looked like something you could peel up with your fingernails. Cold seeped through the seam—not weather, not wind, but the temperature of a room that wasn't a room.
"Bad idea," Ethan said, and even he could hear how calm he wasn't.
Ben twisted the knob. The door opened a hand's breadth.
The cold wasn't air; it was a suggestion with edges. It reached in and laid itself along Ethan's fingers where they hovered near the gap, measuring each knuckle like a tailor deciding whether he was worth the fabric. The smell of old metal sat on his tongue.
"See?" Ben whispered, because humans were the kind of animals who demanded witnesses. "Nothing."
The door drew wider of its own accord. Not a slam, not a jerk—just a confident pull, the way an elevator door takes you because it has places to be and it's polite enough not to leave you behind.
Ben swore and yanked back. The knob slid in his grip. Ethan grabbed the door; Liam grabbed Ben. For a moment the three of them were an ugly chain straining against a plan that hadn't accounted for them. The gap widened another inch. Beyond it: not a hallway, not floor tile, not anything. A shape of nothing.
"Say your name," Liam said, breathless. "Full."
"Ben," Ben said, then, "Benjamin Reynolds," like he was at roll call in the dark.
The pressure eased, like a hand relaxing. From the hall came Ethan's voice, patient as rain: "Let him go. He's not part of it."
"How generous," Ethan said. Humor arrived exactly when he didn't want it and refused to leave. "What am I part of?"
Silence studied the question.
"Open the door," his mother said from the hallway, perfectly, terribly.
Ethan lost a finger's worth of grip. The cold slid into that small permission. It would take the rest if he gave it another inch and call the deal fair. He thought of the fogged mirror and the two lines marked into it—counting? Warning? Practice? He thought of the rule. Do not open the door.
"On three," Liam said. "We take it back."
"Slamming implies we own it," Ben muttered through his teeth.
"On three," Liam repeated. "One."
The thing outside made a pleased little sound.
"Two."
The suggestion in Ethan's bones turned sweet. It would be easier, it offered. It would be quiet. It would be over.
"Three."
They pulled. The door returned the way it had been taken—without hurry, as if time belonged to it. The latch kissed the strike plate. The chain slid home. The deadbolt turned with the friendly thunk of something designed by a human being for other human beings.
The cold was gone between one breath and the next.
Ben sat down hard and laughed the thin laugh of a person who had almost been replaced. Liam stayed where he was, forehead against the door, eyes shut. Ethan examined his hands. Gray smudges dusted his fingers, like ash he couldn't rub away. When he looked at them straight-on, they were nothing. When he caught them at the corner of his eye, they were there.
His phone buzzed.
Thank you.
He typed: For what.
Dots. Stop. Dots.
For not letting me in. Next time, it will knock on a different door. Sleep while you can.
The three of them did not sleep. Ben stacked the furniture against the door—desk, chair, beanbag—as if weight could teach a rule to respect itself. Liam sat with his back to the wall and watched the seam where light had been and wasn't. Ethan perched on the windowsill, curtain cracked, rain scribbling the glass. The city looked like it had been erased and redrawn in pencil.
At two a.m. exactly, the hallway lights brightened to their usual anemic glow. A door down the hall opened and closed. A toilet flushed. The building remembered it was a building.
"On the thread," Liam said finally, voice hoarse, "the poster wrote a follow-up. If it knocks again after you refuse it three times, you move. Three refusals means you're marked."
"We refused once," Ben said. "And we didn't open."
Liam picked up the mirror. Fresh condensation filmed the glass. A single neat tally was drawn through it, the stroke clean, like a teacher's first mark on a board.
"One," Liam said.
Ethan's phone lay warm in his palm. He wanted to block the number and couldn't. He wanted to save it and couldn't. He wanted to ask who are you and understood that every answer would be a mirror.
They drifted into scraps of sleep. Ethan dreamed of a door that was also an eye and woke with the certainty that the dream had not stopped when he did. Morning smeared gray across the world like chalk. By nine, campus moved again—umbrellas like beetles, coffee like confession.
A note lay under their door when Ethan finally worked up the act of opening it in daylight. The paper was ruled, the handwriting careful, the corners damp.
Third floor. Room 312. If you heard it last night, read this.
Rules:
1. Do not open the door at midnight.
2. If it answers in your voice, slide a mirror under the door. Do not blink first.
3. If the hallway lights go out, you have already done something wrong.
4. If you refuse it three times, move.
5. If you think this is a joke, I hope you're right.
There was a name at the bottom and a phone number and a final small sentence that made Ethan's throat feel too narrow.
It took my roommate at 12:17.
He folded the paper and slid it into his pocket. His hands left gray fingerprints on the margin where his skin touched. The smudges didn't show when he stared. They waited at the corner of sight where rules lived, patient as a knock.
That night, at exactly midnight, someone knocked three times on the door across the hall.
They did not open it. The building did not congratulate them. The rain started again, as if it had only stepped outside to take a call.