Calendar, rules and classes

The calendar

The Institute counted its days from the breakthrough in the mine: the day the shaft crew found the rift became Year 1, month 1, day 1 (T-001). Every file, log and memorandum is dated in that calendar, by year, month and day, and the files of the catalogue stand in the order the Institute found its thresholds. The lost expedition also counted its days past the threshold (the expedition's field log, a journal find), and the colony on the planet kept a calendar of its own, which the Institute did not use (T-045).

The years that matter most are these. In year 1 the rift was found and the chamber poured (T-001). In year 11 the first room turned (T-008). In year 20 the first Director stepped down (T-013). In year 24 the first survey went through (T-017). In year 32 Anneli Sund's expedition was lost (T-031), and from year 34 the Institute sent only retrieval runs (T-034). In year 43 the pollution came home from the planet (T-047). In year 48 the rift was widened and the site abandoned (T-055). Tomas Rehn dated the last file in the same calendar, since it was the only one he had kept (T-056).

The rules

The Institute had three rules, and each was paid for. The first was painted on the chamber door in year 1: "No one enters T-001, touches it or puts any object into it without the written order of the Director" (T-001). The second was written in year 4, after the shade took a crew in the unlit tunnels: "From today: light everywhere." (T-004). The third came in year 9, after the mirror: nothing in the cells reflects (T-007).

Under the rules stood the standing orders of the guards, several of them written by Mara Okafor. Never turn your back on a stalker (T-002). No guard holds a door against a brute alone (T-003). No one answers a voice, a step or a knock until they see who made it (T-005). Never take a dark room for an empty one (T-008). No one enters a room on the sealed level without a second guard who can see them (T-012). In a room that shows people, count them, and shoot the one that does not belong (T-015). If a thing does not move while you look at it, do not stop looking (T-016).

Beyond the rift the surveys kept a manual. Its first edition was written after the first survey, in year 24 (T-017):

Sleep only on held ground. Date every map. Build nothing you are not willing to lose. If you hear the land rumble, walk to held ground and do not run; you have half an hour. If the ground turns solid under you, you will be put aside. Get up and walk on.

The second edition, a year later, added the two kinds of bubble (T-020):

You will hear a bubble before you see it, and you will see it only at the edge, as a lens. Learn the two hums. Low means slow: you will crawl and so will what follows you. High means fast: you will walk in fed and walk out hungry. Do not sleep in either. Do not bleed in either.

Other rules were added as the surveys met what was out there. No surveyor walks toward an unexplained hum alone, which is Dahl's rule, and no grenade is thrown within twenty paces of a known rift (T-018). On glass the silence rules apply: no shot is fired, no one runs, and every crossing is made one at a time, at a walk, with canteens and tools stowed so that they cannot knock (T-023). In the open, teams walk back to back, the watch is handed over by the words "I have it", and at night the watch is never fewer than two (T-027). No one walks within sight of the land's edge alone (T-028). No one answers a voice that calls their name, and no one leaves a room to find a voice (T-029). A figure in a surveyor's gear is treated as a hollow until it has spoken the password set before the survey (T-031).

Mara Okafor trained the teams to keep these rules before they went through. She had the new teams cross the floor of the old firing range in socks, then in boots, then with full kit, and sent them back to the start every time a canteen knocked (T-023). She had them walk the range back to back, and put out anyone who turned without saying the words first. "It is the first rule we have ever had that takes two people to keep," she wrote (T-027). After the cache mimic she added one line to the manual: count the crates you brought (T-032).

The retrieval runs had rules of their own for what they carried. The lantern is lit only where the team is ready to fight, and never twice in one place (T-034). A gift found on a run is treated as bait until it is proven otherwise (T-036). The compass is asked for little, and asked where the team is ready to fight (T-039).

The orders of the lost expedition were found in its camp (the expedition orders, a journal find):

Do not split up. Do not follow lights. Do not answer voices. Mark the way back at every turn.

Radio the anchor every evening, and turn for home before half the stores are gone, whatever you have found.

The classes

Every file opens with a class, and there are three. The class says how a threshold can be kept, not what it is.

Class I is harmless while it is left alone. A room of this class "does nothing to anyone who stays out of it" (T-008). The rooms that turned are all Class I (T-008, T-016), and so are the nine objects of the retrieval runs (T-034, T-042) and the mask (T-054). The trader is the only creature in the catalogue placed in Class I (T-026).

Class II is dangerous and is held in a cell. Nearly every creature is of this class, from the first stalker (T-002) to the creatures the pollution made (T-048, T-053). The last two files keep the class though nothing holds them: the sealed level was abandoned to the warden (T-055), and of the toxic mutant Rehn wrote: "Nobody holds it, and nobody will." (T-056).

Class III cannot be held. The rift itself is the first: it "cannot be held, only kept" (T-001). The shifting land and the other places beyond the rift are of this class: "Shifting land cannot be contained. It is managed." (T-017). The pollution is the last of them. Rehn's tests ended on four words: "It cannot be held." (T-047).

In the catalogue the classes stand like this:

Class	What it means	Files
Class I	Harmless while it is left alone	20
Class II	Dangerous, and held in a cell	25
Class III	No cell holds it for long	11