The world is different, and yet the same. Muggles have began to colonize the stars; wizards, not to be outdone, have followed suit. An enterprising Muggleborn had invented a wonderful new spell, a spell very much like Apparition, but so much easier, so much more reliable. With this discovery, traveling to the stars is suddenly all too possible, for one need fear no longer the dangers of getting splinched in the dark vastness of space. But Severus sees none of this, cares for none of this, not when he has so much trouble living on just one planet, in just one country.
Trouble follows Severus wherever he goes. In the 150 years that he has been gone – lost, lost behind the Veil, twisting, turning in the nothingness – the barrier between Muggle – no, not Muggle, how shocking, how old-fashioned, how derogatory, we now call them magically-challenged, Mr. Snape, you should know better, Mr. Snape - and wizard seems to have dissolved so much more. Severus has no doubt that it is the work of the Muggleborns, the children of two worlds which have effected this change. They could not do so in his time, when the society was more stratified and he knew his place – lowest of the Muggles, lowest of the wizards – but now, now things are modernized, now things have changed. The Muggleborns, the halfbloods, have come into their own at long last.
He, the Muggleborn, should find comfort in this. But he can only feel loss.
And one day, he has had enough of his loss. The researchers and healers try to keep him for further study and experimentation; he silences their demands with threats of lawsuits. The historians try to keep him for further questioning and information; he sneers at their questions and talks ill of Potter whenever he can. Few others are interested in him, relic of the past that he is; he has nothing and no one to tie him to this new world, this unknown hell, where people dress differently and talk differently and even brew Potions in a new, modernized way – cauldrons, Mr. Snape? Oh no, no, we don't use those, how terribly outdated – and he'd never thought that he'd come to hate a word so much as modernized, but now he does. So he leaves the modernity, leaves the world, and settles in a quiet Muggle house, where at least the unfamiliarity is what he would expect from Muggles and the friendly looks hide no knowledge of his identity as a centuries-old spy. And so he lives and breathes and mourns through the days blurring together, until a loud knock on his door breaks the stillness of his Ministry-paid home. And as he stalks to the door and pulls it open, he thinks that he should be surprised to see Black's wild-eyed face glaring at him. He thinks that he should be shocked, when Black pushes past him with nothing more than a derisive sneer, when Severus himself stands back in silent welcome.
He should be. But he isn't. Because the world is different, and yet the same.