The Place
The Underwarrens are a warren of narrow, dark tunnels beneath the old cities, and the warren runs 40 km under the four old cities that have fallen and the falling is where the dark began. The tunnels drop 60 m beneath the cellars and the dropping is measured by the drips, the drip per meter, and the drips are the warren's only clock. The passages are 1 m wide at the best and at the worst they are 60 cm, and the 60 cm is the width the warren keeps for those it has decided to keep, in the black of the deep, and the black is the warren's only color. The light of the warren is the claw, the grey phosphorescence that the wall-grown fungi keep along the seams, and the grey shimmer is the only day the deep below the cities has. The warren smells of wet earth and of the old cities' ash, and the ash is where the warren keeps the names of the cities that are gone. This is the place where the silence is kept, and the silence is broken only by the drip and by the word, and the word is the warren's only voice.
How They Live
The Rat Men dig their warrens in chambers of packed earth and worn hide, the hide stretched over the earthen walls to keep the damp from the sleep, and the sleeping is done in shifts of eight because the sleep of the many is the warren's only warmth. The chambers hold a hundred and the hundred is the most the 1 m of passage can keep. Light is the claw, tapped at the seams in the slow grey shimmer that carries along the tunnels, and the shimmer is where the warren keeps its one lamp. Food is the warren itself: the small game that the old cities left behind in the cellars, the fungus of the walls, and the patience that keeps the hunt honest, for the rat man does not chase and the not-chasing is the warren's only law of the hunt. Water is drawn from the springs of the deep, which come up through the old cities' broken sewers in three places, and the springs are kept by the claw-keepers, who meter every drop because the drip counts the meters. The defense is the warren itself, because a visitor who steps into the tunnel is already in the path of the hunt, and the hunt is the alarm and the welcome and the sentence. The day is measured by the hunt, which is also the calendar, because the warren is the only clock the claw needs. The rite of the deep is the first drop: a stranger who wishes to pass is given a drop of the spring water and must drink it in the dark, and the drinking is the only key the warren has.
People
Home of the Rat Men, whose warrens are counted by claw, and the claws keep a thousand souls in the four cities' dark, the thousand being the most the drips can count at once. The warren of the first city is the eldest and the eldest is where the claw-keepers are chosen from, and the choosing is the only rank the rats have, for the rats do not have kings and the not-having is their only law. The claw-keepers keep the fungi, the springs, and the count of the game, and the keeping is the only work the dark values. No one who has been above the cities for a season is welcome in the deep, and the not-being-welcome is the warren's way of keeping the dark honest. A human scavenger who has come down to the old cities calls the Underwarrens the city that never went away, and the calling is his only word, because the city is not there and the rats are.
In Stories
The place where the patience is the only honest thing, and the thing is the hunt, and the hunt is the word, and the word is the end. It was in the first city's deep that the Forgotten drank the drop of the spring, and the drinking bought them the dark and the dark is where the story's longest silence is kept. The hunt has not stopped since, and the silence is the warren's way of keeping the patience.