Worldbuilding Notes | The Underlayer of Saint Tranya — The Things Spectra's Map Files as Noise

(Compiled by readers. Does not represent Spectra's official position. For reference only.)

The official account is that Saint Tranya has only one map: the one Spectra maintains. Streets, floor levels, foot traffic, freight — updated in real time, error approaching zero. Wherever you want to go, it has already worked out the shortest path.

People in the Underlayer will tell you there are two.

The first is Spectra's. It records everything Spectra acknowledges as existing: the 7 maglev lines running 24 metres, 42 metres and 86 metres below ground, and which card was swiped at which gate, all of it filed. The last row on the official level chart reads Source-Stone cooling layer, 412 metres down.

The second map has no name. What it records is what Spectra does not acknowledge: places drawn as solid wall that in fact have a door; substations listed as abandoned that in fact have people living in them; and the phenomena that get closed out, every single time, under ambient noise.

Start with the procedure. Every error code Spectra throws lands on some operations worker's desk, and there are only 3 things he can do with it: archive, reassign, close. Reassignment needs a written reason, and the reason needs a signature from one level up. Closing needs neither; you press it and it is done. An error code filed under ambient noise · auto-corrected drops off the active list 90 days later.

Operations workers in the Underlayer, couriers, people who deal in black-market data — each of them carries half of the second map in his head. They do not draw it, because a drawn one disappears. They keep it in memory and say it out loud once, face to face, when they hand over a shift.

The one mentioned most is that corridor in the south of the city: walk to the end and it should be a dead end, yet it takes you through to somewhere else. Then there are the several cameras whose footage drops a frame by itself every so often. And late at night, certain frequency bands pick up signals that were not sent by a person. Regular. Repeating.

That business in January of Kaiyuan Year 1010 was talked about down there for a long time. A shed frame under the city collapsed on one side and a load-bearing beam salvaged from the old city came sliding down, a little over 4 metres long, 300 kilos at the least. Someone caught it bare-handed, pushed it up and set it back in place. On the surface accident log, that square for that day is blank.

These past few months the news tickers in the city have reported someone like that every few days; the official word is Awakener. Down below, the first thing people do on meeting is run a cheap little ability over you like a ruler and scrape out a letter somewhere between E and S. The ones who come up blank are the real trouble.

There is one more thing on the second map, and the people down there dispose of it in a single word and never elaborate: those who can see what the first map cannot, they call Observers.

A common misunderstanding needs clearing up here. The Central Spectra Monitoring Center has 360 observation stations, and the people who sit at them on shift hold the job title of monitoring officer. The Observers the Underlayer talks about have nothing to do with that title, and nobody hands it out. There is a saying down there: "In this city, the man who sees too clearly lives the shortest."

The other thing we get asked is whether you can buy a copy of the second map. There is no paper edition, and anyone quoting a price is a swindler. If it has any physical form at all, it is the marks — the rock face above certain openings has been painted in dark red, layer on layer, crooked but pressed hard. One of them reads Beyond the Line.

Money in the Underlayer turns on the second map too. After Source-Stone stockpiles ran dry, a kind of crystal the size of a palm started showing up on the stalls, its fracture face like a lump of sugar snapped open by hand, a pale green-white light shuddering through it in pulses. It does not keep and it is not stable, but it generates power. When it changes hands nobody asks where it came from; they ask how many, and how much.

All of this may of course be superstition. How could a city Spectra runs down to the millisecond possibly have a second map?

We can only lay out what is on the record. In Spectra's public archive, the category ambient noise · auto-corrected closed 4,120 entries over the 31 days of January, Kaiyuan Year 1010, nearly 30 per cent more than the same month the year before. Not one of those 4,120 came with the raw sensor data attached.