They leave pawprints where your eyes cannot track them, evaporating like fog in the sunlight before you've even stirred your head from the pillow. If you sleep at night, their eyes glimmer in the dark, star-whirled and slitted. Their fur is the black sky that holds them, and their howls are the chirping of crickets or the whisper of wind in the night.

If you sleep in the day, they are simply grey, though their eyes are blue as the sky and streaked with fluffy, cream-colored occlusions. Less beautiful, but perhaps more precious, the grey cats pace the walls with silent footsteps, brushing impossibly soft fur across the baseboards, flicking their tail, twitching a nose. They brush narrow cheeks against the cracks, the crevices, the weak points in the barriers.

They are, you see, the experts, the scouts, the oracles, marking out the targets before they evaporate. The cloud-eyed cats, at dusk, simply evaporate, melding away into nothing more than shadow and dust.

Thousands more are the star-eyed cats, and they come always in pairs, and with the soft whisper of a suggested purr. They tread across the blankets and chests of their owners, meowling longingly for a scritch behind the ears, a smoothing of their fur. Even in pairs, the cats of the night are lonely, and short-lived, and they fall in droves.

The cats of the night are thieves, gleaming black fur moving across pairs of socks, a key, a hair tie. The cats of the night ravel up passphrases and numbers and codes, and they are villainous bandits of the paper-strewn desk. The forgotten, the inconsequential, the minute detail, they inhale. The child who shall not be born or known, the book not written, the blackout after a long night of drinking.

Sometimes, rarely, the potent memories of a crone or an old man. These, they take sparingly, and only with need. These, they take only in love.

For the cats of day and night love you.

At night, the star-eyed cats stuff the cracks in the world. With lost socks, lost papers, lost memories, meowling softly, they shore up your baseboards. They walk through walls and doors; they carry squirming regrets clenched between their jaws. They die in droves to despair, to dark things that have no names or form, to things that must never have names or form. And in silent vigilance, they follow the markings of the cats of day, though they meet only in the scentless musk of grey. And in silent vigilance, they are forgotten, even as forgotten things shore up the lines between sleep and dream.