The flash in the distance presages the incoming storm. He stands at the window, unwilling to open it yet, until better proof of the cool change comes. On the other side of the room, the sheets shift and the heavy breathing of overheated sleep resumes. Severus watches the lightning play on the far-off mountains, their silhouettes outlined by the bursts of light.
(On the other side of the world, it is winter).
He's used to the difference in the seasons. Almost. Easter is usually wet anyway, and Spring and Autumn are the same as they've always been. There are enough deciduous trees around the Bay that he can watch the leaves turn, and the winters here are cold and wet and grey and miserable, just the way he likes them. Snow he can take or leave. But summer ...
(On the other side of the world, the snow makes the daylight blue.)
Summer is intolerable, heated, made up of screaming children running under hoses and combined with Christmas cheer. He hates it. Hates the emptiness in his life, the need to hide, the lack of anyone to talk to. Even as the despised Potions Master, he still had the staff and the students to sneer at. Now, the little contact he has is limited to the cheery git at the shopping centre who greets him at the checkout and always makes him feel grumpier. That, and what he pays for. Which leaves him sated, but hollow.
(On the other side of the world, the plates have been cleared and the Great Hall has been dimmed. A flurry by the entrance means that Hagrid is about to enter with the pudding, flames leaping high and threatening his beard again. All the students will be cheering, and the Headmistress will start the singing. Cold winds will shake the windows, but the Hall will be warm and safe.)
The storm slides closer, and the windows rattle. The wind won't be cold, not by a long shot, but it will be marginally cooler than the interminable sweltering day. He does not turn as a figure slips from the bed and into the bathroom to try and shower away the heat. Instead, he tries to remember being cold and wet as a child, with the snow leaking into his worn shoes and through his threadbare coat. Now the chill is internal, and will not go.
(On the other side of the world, the snow is rattling against the window glass, its attempts futile. Warm food and good company will bring a warmth to all of Hogwarts, united at last and open to all. Except him.)
Wordlessly, the slim figure behind him dresses, dons shoes, leaves. Severus does not turn as the bedroom door closes, neither does he flinch as the front door bangs shut when the change's wind catches the handle from the departing figure's grasp. Today was Christmas. Tonight is nothing. Tomorrow will be another day. And yesterday cannot change.
(On the other side of the world, no-one spares him a thought. They think him dead, buried, gone and cold. They're half right)
In his world, it is forever winter.