Every October the city runs a little thin.

You notice it first at the creek. Shoal behind Pease Park slows at dusk the way it always has, but in October it slows past still, and for the space of one breath the current leans the other way. People who walk there every evening stop mid-sentence. Dogs sit down. The grackles on the footbridge railing go quiet in the middle of an argument and wait, heads tilted, as if someone in another room has said their name.

Then the water remembers which way it was going, and everyone pretends they didn't feel it.

The Lanternwright felt it on the first of October, hanging tag 412 from a cottonwood. The lantern turned on its wire without any wind. Down the bank, 037, the first one, the Listening Vessel, gave its single note, the E it only ever gives back when someone sings it. Nobody had sung anything.

He wrote it in the ledger, because that is what the ledger is for: Oct 1, 7:14 p.m. 037 answered no one.

The second thing people notice is the house.

It is on a block you know. You have walked it a hundred times. There is the bakery with the chalkboard, there is the blue duplex with the bottle tree, and between them, where there has always been a narrow gap full of cats and recycling bins, there is a narrow white house with a single window where the door should be.

It is not frightening. That is the strangest part. It looks like it has been there for years and is mildly embarrassed you never noticed. Its window glows the color of a paper lantern. If you stand close enough you can hear, very faintly, a fridge humming inside, and something that might be a radio between stations.

People call it the Hollow House, after the old lecture: the cave is not known by its walls, but by what spills out of it. Things spill out of the Hollow House all month. A brass key on the sidewalk in the morning, warm. Candy corn in a neat spiral on a bus bench. A cat, black, who walks out through the window as if it were a door and goes straight to the library.

Thirteen doors are inside, the people who have been in say. Each one is locked a different way. Each one opens onto a different October.

The third thing is the voices.

They are not ghosts. That word is too heavy and too sad for what they are. The people at Central who listen to the old antenna call them Echoes: frequencies that were always here, sharing our space but not our band, the way a radio station shares the air with every other station until you turn the dial. Most of the year they are below hearing. In October the Bandwidth thins, and they come through: a theremin note from a graveyard, knocks under a couch, a planchette that moves a quarter inch on its own.

Teal ones are friendly. Violet ones are lost. Nobody knows what color the quiet ones are.

Riley, who climbs the green towers at night, says Echo, her bat, hears them first. He hovers in place and chirps at nothing, and the air ripples where the chirp lands. She says if you watch the ripple long enough you can see someone on the other side tending a garden that overlaps with yours, and that they always look up as if they'd been waiting.

The Lanternwright went back to the creek on Halloween night with a thermos and a cheap radio.

He tuned it slowly, past static, past a voice reading numbers, past something that sounded like a cat deciding whether to purr. At the exact middle of the dial the static thinned to nothing, and in the nothing a voice said, clearly, calmly, as if reading a sign:

The creek runs both ways here.

He looked down. It did.

He set the radio on a stone, let it play, and hung lantern 413 from the lowest branch he could reach. Its tag turned once in the windless air and settled, facing the water, listening.

To be continued in every room of the Hollow House.