He hadn't known what day or month it was, hadn't even known what year it was, until he had seen that newspaper. Twelve years. It seemed like they had passed both in a flash and excruciatingly slowly. He found himself in a town, the first town he had seen in so long. There seemed to be more cars than before, more traffic, more noise. It was blessed to his ears, after so long listening to the screams of insane prisoners. But it struck him, alone in that busy town, just how lost he was. He didn't know where he should go, did not know where Remus would be living, or Harry, or Peter – well, he knew where he was Pretending to be a pet rat like the coward he always had been.

Contempt and disgust overwhelmed him, and still, that question that had haunted him in his cell: why? He had thought Peter one of his best friends, had trusted and loved him like a brother. They all had. And Peter had thrown that trust right back in their faces, had gotten James and Lily killed. Sirius growled low in his throat, canine impulses strong as always. He wanted to find him right now, wanted to rip him apart. He knew he was angry enough, strong enough, mad enough. But the tiny rational part of him left told him that it was a fool's errand. He was still exhausted and weak, and needed sleep and food before he went any further. He found a bench in a park, and curled up in the grass beneath it. Despite his racing mind, he was asleep in minutes.

He dreamed of strange things, but no stranger than he had dreamed in prison. Dementors scoured the earth for him, searching everywhere. Peter's laughing face was replaced by his mother's, and he heard that familiar sentence, the one that had haunted him in Azkaban, You're no son of mine, and no Black either!

Remus was there, Remus with his woolly jumpers and soft hair that Sirius had loved to run his hands through so long ago, but no matter how much Sirius tried to speak to him, he wouldn't listen, and then he opened his mouth and said –

"Doggy wake up. Doggy?"

Sirius woke to something poking him, and cracked one eye open. It took him several moments to remember the night before, but his stiff and aching body reminded him. There was a toddler bent by his bench, poking him with one pudgy finger. "Good doggy," said the toddler, clumsily stroking his ears. He reminded Sirius of Harry, though he was a little older – a shock of black hair, and mischievous eyes.

"Matthew? said a woman's voice, and then her face joined the little boy's, and she turned up her nose in disgust. "Come away from the dirty dog."

Despite his condition, Sirius still had some pride left. The words dirty dog made his fur bristle, though as he came out from under the bench and stretched, he had to agree that he was not looking or smelling his best. His fur was matted and smelled unpleasantly of dirt and stagnant water, and mud caked his paws. He still had one toe missing, an effect of splinching, and it hurt.  His body ached, but that was no change. The beds in Azkaban were hard and cold, with one thin sheet and pillow. There had been times in there when he had wondered if soft beds and warm baths had just been a pleasant dream, if all of his friends and Remus had just been figments of his imagination.

Inside those cold grey walls, it had seemed like the prison was all that existed, that any outside life was fiction. But he had not made up the sky, for it was blue above him, nor the clouds, which were like soft candyfloss. He had not made up the sweet smelling grass or the colourful flowers. He had not made up Peter Pettigrew, who had looked at him through a photograph, and so he hoped with everything in him that he had not made up Remus, nor any of the others.

He planned to go to Hogwarts, to wait for Peter, but he knew he had to see Remus first. It took him some days to get to Yorkshire, sleeping in parks, living on scraps people threw to the black dog. When he got to Yorkshire, he found a telephone box. Sirius was glad to know that phonebooks were still a thing, and hoped that Remus was still using a telephone. He ran a finger, tipped with a long and dirty nail, down the page, desperately searching for the L's. The telephone box was crammed, and smelled of piss and alcohol, one window smashed.

He hadn't had any money, but a few mislaid pennies in drains and mud had been enough. The evening had been long and bright, forcing him to wait agonising hours. He knew he only had a matter of time out in the open. The Ministry didn't know he was an animagus, but they'd find him sooner or later. His hands shook as he found him, black ink on the dirty page. Remus J Lupin. Sirius punched the numbers into the telephone, not even sure what he would say when it was answered, not sure if he would even be able to speak. His breaths were ragged as he waited, the dialling tone driving him crazy. And then the phone was picked up, and his breath stopped.

"Hello?" said the voice on the other end, and Sirius froze. It was a woman's voice, tired, slightly worried.

The line buzzed in his ear, and the woman spoke again. "Hello? Is somebody there? Hello?"

Sirius managed to unfreeze himself, slamming the telephone back into its cradle. He took a breath, ran a hand through matted hair. Perhaps he had the wrong number, the wrong Remus J Lupin....but how likely was it that there was more than one Remus J Lupin in Yorkshire? Then who had the woman been? Remus had no sisters, and his mother had died while they had been at Hogwarts....perhaps she was a cousin, or a friend, or a neighbour or something.....yeah that was it, had to be, somebody popping over to check up on Moony. It was just after the full moon, after all. Remus was bound to still be weak. But Sirius couldn't stop the niggling feeling, the voice that whispered that Remus hadn't answered the phone because there was no Remus, his Remus, there had never been, or that he had died –

Sirius whimpered, covering his face with his hands, clawing as though he could drag the thoughts out. "Stop it," he muttered. "Stop it, stop it, stop-"

It had been the same in Azkaban, this voice, whispering that maybe there was no real Remus, no real Sirius, even, that their time together had been a fabrication, that everything in his life that wasn't a hard cold cell had been a fabrication. Sirius' worst enemy was his own brain, and he couldn't help but feel sometimes that it won every battle.