FLOOR B-13
A sub-basement that presents as an ordinary office and is not one. Almost no one who enters returns. Something on B-12 can hear them.
ENTITY / LOCATION / SUB-BASEMENT / DO NOT ENTER ALONE
OVERVIEW
SW8's premises comprise four storeys and one basement. This is confirmed by the lease, the survey, and the fire safety assessment. The lift, however, offers more buttons than the building offers floors — a recurring property of the premises; see also the Tenth Floor, which is upward, voluntary, and pleasant. Floor B-13 is the same phenomenon pointed in the other direction, and it is neither.
On arrival, B-13 presents as a comprehensively ordinary office: open-plan desking, fluorescent tube lighting with the usual two flickering near the far wall, a bank of glass-walled meeting rooms named after rivers, a kitchenette with a fridge containing other people's labelled lunches, and a low, even hum of air conditioning. It is, by every first impression, the least remarkable floor in the building. This impression holds for exactly as long as you can see the person you arrived with. It does not survive the moment you cannot.
THE PROPERTY
The defining property of Floor B-13 is this: once you lose sight of a person, you cannot find them again. Not "it is difficult." It is, in the observed record, impossible. Two people stepping apart to check adjacent meeting rooms — Thames and Lea, doors four metres apart — have failed to reconvene. The doors, re-checked, open onto corridors that were not there on entry. The corridors continue. They continue further than the floor plate permits, further than the building's footprint permits, and, on the testimony of the few who returned, further than the city permits.
- The meeting rooms named after rivers number six on entry and an indeterminate number thereafter. A returning clerk reported passing "Thames" forty times, each a different room, one of which contained a previous version of the same meeting they had left.
- The fluorescent lighting is continuous and identical in every direction, which removes the sun, the time, and eventually the conviction that any direction is more "out" than another.
- Distances do not compose. Walking thirty metres north and thirty metres south does not return you to the start. It has, on one logged occasion, returned a clerk to a corridor "above the one I started on, somehow, while still going down."
- The carpet tiles are laid in a pattern that, photographed and assembled later, is a repeating fractal — self-similar at the scale of a tile, a corridor, and, where the floor plan could be reconstructed at all, the floor itself.
REPORTS FROM FLOOR B-12
Floor B-12 — the floor immediately above, accessible, ordinary, and well within the building's actual dimensions — is otherwise unremarkable except for what staff working late there have heard coming up through the floor. The sound is described, with unusual consistency across independent witnesses, as a roar: deep, resonant, unhurried, and — in the words appearing in four separate incident reports without those witnesses having spoken to one another — "a bit like a minotaur."
Staff member working alone on B-12 at 02:17 reported "a sound like something very large becoming frustrated with a corridor" directly beneath the floor, followed by a period of silence, followed by the same sound "much further away, but only because the corridor had moved, not because it had." The staff member left B-12 and has requested not to be rostered below ground again. The request was granted without discussion.
Facilities, investigating the roaring as a suspected HVAC fault, lowered a contact microphone through a cable duct toward B-13. The recording contains forty seconds of the air-conditioning hum, then the roar at close range, then a second sound the audio analyst logged as "hooves, or something doing an impression of hooves that has only ever read a description of them." The cable was retracted. Eleven centimetres of it were missing. The cut is clean. It is also warm.
RETURNEES
Almost no one who enters Floor B-13 returns. The exceptions are rare, and they come back changed: battle-worn, half-starved, dehydrated, and reporting durations wildly out of step with the time elapsed upstairs — a clerk gone for an afternoon by the building's clocks has returned convinced of months. Their accounts, while individually incredible, are mutually consistent, which is the part that has stopped anyone laughing.
Entered to retrieve a box of archived invoices. Returned nineteen days later by the building's reckoning, having experienced what they estimated as "most of a winter." Lost 6kg. Described "hallways that branched into themselves," staircases that "went down to arrive higher up," and a far-off bellowing they navigated by, "because at least it was always somewhere, and everywhere else was only more corridor." Still employed. Now keeps a torch, a water bottle, and a ball of string at their desk. Has never explained the string. No one has asked.
A new starter who took the wrong lift button on day one. Returned, by their account, "considerably more experienced than my job title," with a hand-drawn map covering forty sheets that, laid out, does not tile flat and cannot be made to — the edges that should meet are the same edge, drawn from two angles that cannot both be true. The map has been to a topologist. The topologist confirmed it depicts "a space that is internally consistent and externally impossible," kept a photograph, and has since become noticeably quieter in meetings.
Returnees uniformly report that the roaring is not, in the end, the dangerous part. The roaring is somewhere. The dangerous part is the long stretches of perfect, humming, fluorescent office where there is nothing at all — no sound, no exit, and no one, because the moment there was someone, you looked away.
THE CENTRE OF THE MAZE
The minority of returnees who kept their composure long enough to navigate by the roaring — toward it, against every instinct — report that the corridors are not endless after all. They converge. Somewhere near what the fractal will admit is the middle, the carpet tiles give way to poured concrete, the fluorescent hum drops an octave, and the office stops pretending to be an office. At that centre, three independent accounts agree, there is a door that is not a meeting room, and behind it a chamber, and in the chamber an aperture — a working portal, with controls, that goes somewhere the building's plans have no room for at all.
This entry concerns the labyrinth. The thing at its centre — how to reach it, how to survive the bovine cryptid that paces between you and it, and what has happened to the teams who have tried to operate it — is documented separately, deeper, and under stricter handling. Floor B-13 is, in the end, only the corridor. The Aperture is the reason the corridor is guarded.