It was a strong, ten o'clock light that shone in from the cell window. It was cut into even strips by the rusty iron bars, illuminating the grimy stone floor in long, orange-gold stripes. There was dust in the air, speckling the bright light. If he focused, Sirius could hear birds chirping outside. He would get up and see the Quidditch pitch, but he was bound to the wall by heavy irony chains that clinked at the slightest movements and sent the Dementors whirling suspiciously in his direction.
The prevailing feeling was boredom, really. The walls were always cold and hard, the floor always crawling with a few insects and growing the occasional creeping sample of mold. "James," he said. "I'm bored."
There was James, sitting at the other end of the cell. His back was against the wall, legs stretched out before him. He was wearing gray slacks and a bright cerulean jumper that Sirius thought didn't suit him very well. "I know, mate," James replied.
"Don't you have anything to do?" Sirius whined. "Look at me. Bloody chained, I am." He held up his wrists and jangled them at James.
"I know, mate," James repeated sympathetically. "Nothing I can do though. You deserve it."
"No I don't!" Sirius shrieked suddenly and loudly. "I don't, I don't," he added more quietly, but with the same underlying tone of fervent hope, urgently wishing that he could convey his innocence.
"You deserve it," James said again, with a mild shrug and an unreadable expression. "Nothing I can do."
"Listen to me, James!" Sirius whispered urgently. "I didn't do it! I never betrayed you! It was Peter…"
"How can I know?" James answered simply, shrugging again and nestling further into the wall. "A flash of green light, then nothing. What do I know, Sirius?"
Sirius sighed. "James, you're my best friend. You have to understand. When I told you to pick Peter, I never imagined…"
James pushed his slipping glasses up his nose. "Nothing I can do."
"You can listen to me!" Sirius fired back fiercely. "Please – I never wanted you or Lily dead! And certainly not Harry." He sighed as he recalled the soft warm shape of baby Harry in his hands, but only glimpsed it for a quick moment as it was sucked away from him, tossed into the blackness. Harry's adorable green-eyed plumpness was replaced by James' gaunt corpse splayed over the rubble in the cold midnight. "I never, ever wanted that," Sirius said.
"There's no way you can prove it," James pointed out, rather harshly, chin jutting out defiantly.
"You have to know!" Sirius roared, face contorting in anger, sitting up as much as his chains would allow. "I never wanted to see your corpse, on the ground like that! I never wanted to see you dead! James, you know me better than that – you know I would never sell my soul to Voldemort."
"Yet, here we are," James mused accusatorially, choosing not to meet Sirius' burning eyes.
"I'm innocent," Sirius whispered, anger giving way to quiet pleading, a yearning to be accepted and comforted.
In that instant, James flickered out of existence, leaving the bare stone corner in sight. Sirius blinked a few times, wondering if he was imagining things. James had just been there. "James?" he called out tentatively.
He flickered back, still wearing that cerulean jumper, eyes fixed intently on Sirius, as though he had never left. "Sirius…" he began, voice harsh and throaty from disuse.
"You're right," Sirius said, horrified. "You're right, I did kill you!"
"No, wait, hang on – "
Sirius cut him off: "No, you're right, you're absolutely right!" In his agitation, he had begun to wring his hands, and the chains rattled incessantly like a miniscule train stuttering along the tracks. "It's all my fault! If it weren't for me and my stupid idea, you would still be alive."
"And you'd be dead," James said clearly, leaning forward and enunciating every syllable. "Look, Sirius, things happened the way they were supposed to happen. The war is over. Be happy."
"No, no, no, I can't!" Sirius said loudly over James' calm voice. "I can't, see? I killed you! I killed Lily…!"
"It's all right, she forgives you." James smiled gently, as though Sirius were a very petulant five-year-old. "Look, mate, relax. We know. We've forgiven you. You're innocent."
Sirius stared at James in concentration, brow furrowed. "I didn't kill you?" he asked finally.
"No," James replied firmly. "You didn't kill me and you didn't kill Lily. It was a brilliant plan that went wrong."
"So, I'm not the murderer," Sirius clarified, sitting back, stunned at this epiphany.
James kept smiling softly. "Right."
"So I'm not guilty," he continued.
James nodded. "Right."
"So I'm innocent," he concluded skeptically.
"That's right." James stood up and dusted off his hands. "I've got to go, mate."
"I'm innocent," Sirius repeated, more confidently.
"Good bye, Sirius," James said. "I hope I don't have to talk to you again."
"Wait, don't go!" Sirius cried indignantly. "I've only just realized that I'm innocent!" Even as he said the words James' body was slowly being enveloped by the morning light, leaving the corner in plain sight. "We can have a proper chat now! We can talk about how to get out of here! James!" He had completely disappeared, leaving only the ghost of a smile.
Sirius hadn't even realized that he had thrown out a bony hand in a dramatic fashion, outstretched toward the corner where James had been. He drew it toward himself, and tried yet again to peer out the window. It really was interesting, the way the light played off the rust to burn deep vermillion into the stone at certain angles, and at other angles a mere bright white. If he were able to stand up, he would have tried to see the ocean. It really was quite a nice morning.