One cat of night is called Soot. It is a good name. Traditional, for cats who steal in the night, a stealthy, silent name. Flame accretes on stone, Soot's mother tells him, applying a proprietary lick to his head. He squirms as she tells him this, and a paw presses down. She continues telling him how it is made: a thing she learned from a slim book toppled behind a desk and into their nest. Soot happens silently, as fur is shed. Quietly, like the beloved humans most often sleep. It is a remnant, to be forgotten. She tells him this, hoping he will take it to heart, this mewing ball of black and mischief.

Soot remembers the story, word for word, after Mother Dust swells again after a visit with a cat of day, and after he and his siblings have left the fur-warm nest of forgotten things. But the nature of a cat, and the nature of Soot, is to disobey, even as he loves the humans he thieves from, even as he pads his den with socks and dreams and the bones of monsters.

Soot's mother was right to worry, for he is loud in the night where no cat of night should be loud, tipping over glasses of water, treading over humans. He wakes even the snorers as he stalks the boundary of sleep and dreaming by knocking memories into the floorboards. There is disdain in the set of the whiskers of his fellows, for he is not a very good keeper of dreams, being more prone to waking the dreamers.

But, Soot is a good hunter, and his jaw is clenched tight around his prey night after night: actual rats! Rats of dream! Rats of many color and variety, some of which are the size of pillows or a spare blanket dragged from the bed of humans. His rats are colorful and ever-growing! The shoring up of the boundaries is clumsy, but it is devoted, for though he is loud in the night, Soot loves the humans as much as any cat might. He hunts, he is content. He slips between the bedrooms of hundreds of humans, crouched low to the ground, back twitching, tail going tick and tock, and he loves fiercely, violently, ambitiously.

Is he not a cat? Are they all not cats? Soot is a very good cat. He tells the humans each night, tossing and turning in their beds, half-asleep, half-awake, not quite hearing his voice. The ears of dreamers aren't as sharp as those of Soot's sibs! But his sibs are not as proud as he, or as pleased with his disturbance. It does not matter. He will continue to sing his hunting song, his song of victory. He tells of the large rats, the slow rats, the rats he hunts under the blankets that haunt his charges, the ones that must be biting the fragile humans: the ones he can never quite coerce from under the covers. He tells of the blankets he steals in pursuit of the thrashing rats, and the impending demise of the blanket rats.

Soot is devoted. One day he will catch the blanket rats, and seal up the floorboards so well that the humans will sleep soundly. Then his songs will wake them no longer.

But one night, Soot slips from the window of a dreamer and catches a glimpse of the biggest rat of all.

Many nights Soot has slipped between the walls, the worlds, chasing those things which must be forgotten, and what part of his brain is not devoted (so devoted!) to the hunt, has seen the gleam through the window. The humans sleep poorly on those nights, and it seems the blanket rats writhe even more beneath the blankets, causing the dreamers to writhe with them, no doubt bitten by sharp, evil teeth.

Soot stares at the giant rat in the sky. His mother told him many stories: including the one of the Rat King. Soot's tail lashes as he thinks about it: the king of all the troubles. The other details of the story escape him, but here it is. He is sure. The King of Rats, who will be hunted down to end the troubles the humans have.

He lifts his nose to the sky and yells, long and loud, and the dreamer behind him mutters incoherently, tossing. The rats are fighting back! Soot places his paws to the window and strikes at it, his claws skidding from the glass. The giant thing, the glowing rat in the sky!

A sib goes streaking by beneath him, belly close to the ground, and hisses at him. Soot does not care. The Rat King, he cries to the other cat. The Rat King flies high above, we must catch him! But his sib is between the worlds and away, and the human is stirring.

Soot hisses and streaks off the window ledge. Someday soon, he promises the Rat King.

But the next night, the Rat King has slipped away, and the next there is less, and one night it is gone. Soon enough he begins to see it again, and Soot understands: this is cannier prey than the blanket rats.

Soot thinks on the lessons of his mother as he sits on the peak of a roof, hissing low and mean at the Rat King. The biggest prey requires the fullness of Soot! The patience of fire! And he, the cat of cats, the best cat, will make his mother proud. At last, a rat worth falling silent for!

Night after night Soot sits, absolutely still, in the shadow of the chimney, the fur of his back twitching, absolutely silent. He is soot on brick, a stalker in the night, the predator who will save humanity.

One night soon, the Rat King will be careless. It will slip from the sky.

Someday, Soot knows, he will catch the moon.