A Hoar Owl stands as tall as a child’s knee and spreads wings wider than a man’s arms. Its feathers are white, edged with grey, and frost grows on them so that the bird looks furred with rime; the ice crystals on its back catch the cold light. Its face is a flat white disc, its eyes pale silver, its beak and claws a translucent blue-grey like old ice. It flies without a sound, a slow, gliding drop from a spire to the snow. It does not hoot or call. The only sound a traveller hears is the click of its claws closing.

They live on the ice crags and frozen spires above the snowfields, one pair to a crag, and range widely over the open snow below.

A Hoar Owl hunts by sound. The cold air of the plane carries sound sharp and far, and from its spire the owl hears the scrape of a Stillhare at the lichen or the crunch of crust under a foot a long way off. It waits for movement and drops on it. It is not drawn to warmth and will not attack anything as large as a person standing. It does strike at small things that move in the open: a hand that slips out of the furs in sleep and twitches, a scrap of food, a bird of the traveller’s own.

Its flight is wholly silent even in the brittle air of the plane, where a twig snapping sounds like a blow. Its talons close with a grip that does not open until the owl chooses, and the frost on its feathers makes it all but invisible against the ice.

A pair keeps one crag for life and lays its eggs in a hollow cut into the ice. The young are grey down and grow white as they fledge. A dead owl, frozen where it fell, lies unchanged on the snow.

Their feathers are the lightest warmth on the plane, and the Frost-Born line hoods with them and wear a Hoar Owl’s facial disc as a mark of a patient hunter. Travellers who sleep with their hands inside their furs have nothing to fear from them. Those who do not may wake with torn fingers.

The travellers' tale is that Hoar Owls take the fingers of the sleeping, and many who come home from the Frost-Bound short of a finger blame an owl. Most such fingers were lost to frost, which on the plane can take a finger in a night; the owls strike at a moving hand, but seldom take more than the skin of it. Some Frost-Born hold that an owl on the crag above a camp watches over it, and will not camp beneath an empty crag.