Something crucial had been torn from him over the course of the night and he rather regretted missing the moment.
If he remembered it then maybe he could figure out what it was that had been so carefully ripped from his soul. Maybe he could get it back.
But that, of course, was folly even to think of. He didn't want it for with it would come the horrors of his family − his father's cool glares and hot breath as he screamed in rage, his mother's clawed hands pawing at him to stand up straighter and be polite and be quiet and make conversation and keep your chin up and for god's sake act like a real Black, and Regelus whining and asking why mother and father paid more attention to him even if it was only to have screaming fits with him.
Sirius paused in the street, setting his bag on the curb and trying to reorient himself. He wiped at the tears on his face with his sleeve but stopped when it hurt too much to brush the bruise on his cheek. It was still bleeding from where his father's rings had cut him.
He sighed and collapsed in an uncomfortable assortment of folded limbs beside his bag. It was cold and dark and he was alone and he hadn't gotten his broomstick before his mother chased him out and his face hurt and he had no more home and no more family.
And he didn't know how far James lived from here.
He wanted to cry. All he could hear was his mother's shrieks echoing in his head.
The knight bus came eventually and he was only on it for a few minutes. His hair was still shaggy, despite his parents' disgust, so no one looked oddly at the large bruise discoloring his face.
Things would be alright, he told himself. He'd be at Jamesie's in a bit and Merlin, but his parents were nice. They'd let him sleep there until Christmas break was over and… well, things wouldn't be normal again but…
It had begun to rain. He showed up, the picture of pathetic-ness, at the Potter's door at three at the morning and rang the bell.
He felt a great ass.
As it was, he only had to wait a few moments or so for Mrs. Potter in a floral dressing gown and a bleary eyed James to open the door and gasp at the sight of him.
Afterwards, surely, Sirius himself would laugh at the image he presented to them − five feet and ten inches of pale, dripping wet, sixteen year old boy, clutching a dirty travel bag and sporting a great bleeding shiner on the side of his head.
Mrs. Potter pulled him inside, presented him with no questions but a warm hug, a dry towel, and a mug of chocolate, while James stumbled upstairs to prepare a bed without even being asked to.
As Sirius quietly removed his boots and sipped at his drink a piece of that little important bit of his soul came back.