Azkaban
Azkaban was cold. That was the first sense that Remus registered after Moody apparated both of them to the closest shore away from the prison. The prison wasn't even visible yet, and Remus already felt a chill running through his body. Remus usually ran hot. He hadn't bothered to bring more than a coat, but now he wondered if he should have layered a little more as he put it on. Moody cast a warming charm with minimal effect as the cold seeped into Remus' bones. The boat they were using to cross into the sea was little more than a small rowboat. The water seemed to lap up against it, always in danger of spilling over the sides. Remus kept flinching every time it got close. He had been required to leave his wand in the Auror's office before they left, and he felt rather naked without it.
The second sense that he registered was that it was dark, The small lantern hanging from the front of the boat emitted blue light that barely made a difference, even to Remus' senses. The cold was only getting worse as the prison finally came into view. It was a black monolith that loomed above the two wizards, daunting. Remus silently wondered, No wonder everyone goes insane in there. A smaller voice in his head thought, Has Sirius? Even with the Patronus that Moody was keeping close, the despair of the dementors congealed Remus' thoughts. He was extremely glad he had the foresight to write down the questions he wanted to ask. Presently, he clutched the little scrap of paper for dear life, like if he let go, so would his resolve.
The past month had been a blur. It had felt like meeting after meeting, each person being different from the last. Dumbledore had asked him if he was sure he knew what he was doing. The new Minister, Remus had since learned his name was Cornelius Fudge, had practically interrogated Remus over his intentions for visiting Sirius. Moody and several other Aurors had given him information about the rules surrounding the prison and what he was not to do under any circumstances. Most of it had felt relatively self-evident to Remus: Don't break any of the prisoners out, don't kill anybody, don't fuck with the Dementors, the works. Even a reporter for the Daily Prophet had asked to see him and questioned him about his relations with Black. This last person was the only one Remus had refused to see.
As the prison loomed over them, Mad-Eye asked, "Scared?"
"Isn't everyone?" Remus replied. This seemed to be the correct answer because Mad-Eye only gave a noncommittal grunt.
Their boat landed on the shore, and Remus stumbled as he clambered out of the dinghy. Azkaban's shores didn't have sand. Instead, a mix of round white pebbles and sharp obsidian crystals littered the serf. Remus was certain that if he wasn't wearing his best steel-toed boots, he would have cut his feet on the ground. The actual prison itself seemed to be made of a black brick that was similar to the corridors surrounding some of the Departments in the Ministry of Magic. Only the Ministry's bricks gleamed, no doubt having been polished at least once a month. Azkaban's were dull and mute, creating a cold and dead feeling.
As they walked up the shore, Remus' brain kicked into defense mode. It latched on to any and all human interaction and momentarily forgot his hatred for meaningless small talk, "So...Do you come here often?"
Remus winced at the weak pick-up line, but Moody didn't seem to notice. "A lot more than I used to. After the war, we made over a hundred arrests, but only about fifty of those good-for-nothings ended up here. Most of them were too proud or stupid to weasel their way out of a pardon."
Remus wondered what kind of people were too proud to not defend themselves in court. Wincing again, he remembered Sirius was one of those people. "How many prisoners are usually held here anyway?"
Moody's blue eye bored into Remus again, "Best not to ask questions you don't want the answers to."
With a finality to their conversation, they spent the rest of the trek up the shoreline in silence. Azkaban didn't have an entrance, so much as a back door that only opened when Moody tapped it rhythmically with his wand. There seemed to be some sort of complex combination on it that Remus couldn't even begin to understand. The bricks around Moody's wand, which had been previously blank, unfurled into a jagged hole of a doorway. It reminded Remus of the muggle entrance to Diagon Alley. There were no windows on this level, and Remus probably would have fallen if it weren't for his eyesight.
"Black's on the fourth level," Moody grunted.
They passed rows upon rows of prison cells. Most were empty on the lower floors, gradually filling up as they travelled upwards. Moody explained how on the second floor, prisoners were allowed windows. Some of the cells' occupants rushed to the iron bars marking their cells. Some leered or jeered, some pleaded, begging for mercy. Some of the prisoners didn't rush to see them at all. They just muttered to themselves, rocking back and forth on their beds as Remus and Moody passed. The worst were the ones who didn't react at all, only staring blankly at the walls of their cells. These looked like little more than corpses. They lay there with glassy eyes, barely breathing. On the third floor, Remus forced his eyes to the ground, fearing what he might see if he looked up.
When they reached the fourth floor, Remus finally did look up. He forced himself to search every cell they passed, looking for a familiar curtain of black hair. And halfway down the hall, Remus saw him.
"Black," Moody barked, "You've got a visitor.", and looking to Remus he added, "Five minutes," and stepped back.
Sirius had been sitting on his bed, but he stood after noticing them. He had lost considerable weight, his high cheekbones too sharp, nose too pointed. Stubble covered his jaw and his beautiful dark hair was matted, curled into tangled knots. His clothes were thin and dirty, exposing ghostly white hands and feet. And his face, Remus couldn't bear it, he couldn't bring himself to meet the icy cold stare of his former lover.
Instead, he focused on Sirius' cell, pointedly ignoring how its inhabitant was now shuffling closer to the bars. His walls were as bare as the rest of the prison. His bed was little more than a dingey mattress, resting on a raised slab of blank concrete that covered the floors. Remus wondered how much sleep Sirius got in it. Above it sat a small window with bars over it. There was a small toilet and a sink, but no shower, and no mirror on any of the walls. Remus noticed a couple of newspapers, their dates marked about a month apart from each other. Remus wondered what Sirius could possibly want from a couple of outdated newspapers. He had always hated those things.
Sirius' voice cut through Remus' thoughts. "Moony?" He sounded hoarse, like he hadn't spoken in several days. He probably hadn't. Remus finally forced himself to wrench his gaze away from the broken sink so that brown eyes met blue.
A wave of anger, he hadn't known he could still feel, possessed Remus. How dare Black look at him with that hopeful expression? How dare he turn his sad and gentle eyes on Remus like that might make it okay? Remus wanted to punch him. Instead, he quoted the first question on his list, voice dripping with rage, "What did you do, Sirius?"
Sirius had placed his hands on the bars at this point, his face was pressed against them, sad eyes looking up at Remus. Much to Remus' dismay, they started to fill with tears. Sirius seemed to melt before him, "We switched," he croaked, "Just over a week before Halloween."
The shock of what Sirius meant hit him like a wave. "What?" He breathed, all of the anger rushing out of him.
"It wasn't me, Moony. I-I trusted the rat instead." At this, Sirius finally looked away, tears falling down his cheeks.
Switched?
Sirius had...switched? With Peter? But that didn't make any sense.
"But I thought...Dumbledore said...", Remus stuttered, completely abandoning his notes sheet.
"Dumbledore is wrong," Sirius wailed, bringing his forehead down on the bars, "We changed last minute without telling him. It was going to be the perfect plan."
Sirius and Peter had...switched without telling anyone. That meant that Peter had been...Peter had been their Secret Keeper? And if Peter was their Secret Keeper, then why were James and Lily dead? The questions slowly started to click into place in Remus' head. All of the little idiosyncrasies, all of the gaps in the story Dumbledore had told him. Why had Dumbledore lied? But if they hadn't told anyone, then...of course Dumbledore would think it was Sirius. He probably wouldn't even need a trial, all of the evidence was there anyway. If Peter had sold them to Voldemort...if it was him, then of course Sirius would realize. Of course Sirius would go after him, blinded by rage and vengeance...and of course, Sirius would never betray James and Lily, but...could Peter?
"Why?" Remus whispered. He didn't really know to which question. Why had Peter betrayed them? Why hadn't Sirius said something? Why was Remus the last to know?
Sirius sank to the floor of his cell, and Remus couched down with him. "Because I was scared." A small breath and then, "Because I thought it was you."
And it suddenly made sense. All of the strange pauses during conversations. The way Sirius pulled away during the last few months. How he couldn't quite look Remus in the eye. All of the strange questions Peter had ever asked Remus about his missions. The rumours about the spy suddenly dying out. They hadn't thought that the spy was gone, they had thought that the spy was him.
Remus could be sad later, he now only had half of their time left and still needed answers to a new set of questions he was rapidly coming up within his head, "Is the rat dead?"
Sirius shook his head. "I was so fucking close, Moony. The sneaky shitstain scurried away before I could get my hands on him" His tone had switched to something spiteful. Remus didn't care. He still had several questions he needed answering.
"Where is he now?"
"I don't- I don't know."
"Can you prove it was him?" Remus urged on.
"No"
"But he can?"
"Yes. But Moony, he's smarter than we ever gave him credit for. He's been planning this out for years."
Remus wanted to choke. He hated that there was only a minute left and he was rapidly running out of adrenaline to numb the shock. He racked his mind for other questions he could ask Sirius. "Can I track him?" He finally managed.
"Probably, but you can't let him know you're coming."
Remus was shocked by the venom in his own voice, "Oh don't worry Pads, I won't."
Suddenly a hand was on his shoulder, and Mad-eye behind him was saying, "Time's up". He sounded angry, and Remus tried not to think about what that meant.
Sirius stood up as they turned away. He called through his bars as they were about to leave, "I'm so so sorry, Moony. For everything."
Remus didn't care. They would have time to repair their relationship later. Right now, Remus had a rat to catch.