He froze all over again once he dropped through on the other side. Sank to his knees.

Home.

That's what this was.

He was home.

He couldn't believe how exactly the same everything was. The crimson armchairs by the fire, the gold-spangled rugs covering the floor, the study table by the window… identical. It gave him a sense of vertigo to see it all again, like peering over the edge of the parapets of the castle instead of back through time. Either way, the distance was dizzying.

James sank into one of the chairs, lounged in it, really, like he belonged there every bit as much as he had at sixteen. Seventeen. His whole life, really. When had James never belonged? He looked around the common room, taking it in the same way Sirius was. "I remember this place."

"It looks the same," Sirius said. His gaze lingered on a chip in the frame of Godric Gryffindor's portrait. It had been there since his second year, when an afternoon study session between the four of them had gone awry.

"Does it?" James asked. He glanced around again. "Funny. I think it feels very different."

He was right, of course. As much as this room looked the same, it wasn't. Nothing was alright, and nothing was the same, and someone had to pay for it. Sirius was done being the one to pay for it. He turned toward the boy's staircase.

"Padfoot," James said, and there was a warning note in his voice.

Sirius ignored him and started up. The feel of his heartbeat was like running – speed and intensity and that painful, desperate moment before you either break down or break through.

"Sirius!"

Up one landing, then two. Peter would be on the third. And then he wouldn't be anywhere at all. He'd make sure of that.

"Sirius."

Sirius whipped around. He had to remind himself he was in a tower full of people, full of children sleeping, children who didn't need the burden of knowing what was about to take place. What had taken place to bring him here. He had to remind himself that no matter how solid and defined James looked, standing there with his ruffled hair and his glasses and that determined grit of his teeth, he was not there. And never would be, not ever again.

All thanks to Peter.

"You don't know," Sirius whispered fiercely. "You don't know, you will never know. You're not here, you didn't have to –" he broke off, his throat closed around a sob. "Didn't get to live through it."

James stepped closer. The hands he placed on Sirius shoulders felt like nothing, like dead air.

Sirius looked down. His feet made impressions on the rug. James's didn't. "I did live through it," Sirius said quietly to the floor. "And I wish I hadn't."

James's grip tightened, so much that Sirius thought he could almost feel it.

"I'm sorry," James whispered. "But this isn't. Your. Fault."

"I don't care," Sirius said. "This is the only way I can make that feel true." And he wrenched away and pushed through the third year dormitory door.