When the full moon set, after Sirius had been bitten...
Remus came to on the cold floor, sore and shivering. It was his favorite time of the month - the furthest point away from the next time that would surely come. He was used to his ritual, the words he had always told himself before he opened his eyes and started the countdown to the next full moon. It's over. You've got your friends, and you didn't hurt anybody.
He said it to himself, automatically, because he always had. But this time was different.
They finally knew now where James had gone - they got their explanation at the worst possible moment. Remus had always counted on Prongs, who always came, even after school had ended, and on Padfoot, who always went everywhere Prongs went. When Padfoot showed up by himself, Remus truly felt it for the first time, the James-shaped absence. Remus could tell Sirius only came in the hope that James would show up, finally, but he thanked him anyway.
You shouldn't take it for granted that they're still coming at all , he told himself. Out of school, his condition was no longer an excuse to sneak out at night, so where was the fun in that for the others?
Then, Lily showed up.
Remus was afraid to open his eyes. He knew he would find confirmation that his greatest fear had come true, but there was no avoiding it forever. He could still remember how brutal the first transformation had been, and he did not envy Sirius. But what worried him even more was how good it had felt to finally give in to the wolf.
The wolf was finally sated. It had finally tasted another's blood. Remus had always felt so alone with his disease - and now he'd truly made a friend. What a sick, sick thought it was. You always knew you were going to do that in the end, the wolf told him. A long time ago, he had dubbed this voice the wolf . Though, for all but two days of every month, he was normal, the wolf was always there. All those trips to Hogsmeade - don't tell yourself it was an accident, a coincidence, how you kept going back out. His furry little problem had just gotten bigger. Do you remember how part of you wished Prongs hadn't saved Snape? How you wanted, just once, to know what it would be like?
He finally opened his eyes and saw Sirius was asleep, or rather passed out, sprawled in an unnatural position. You should have killed him. It might have been your last chance. Azkaban is next, or death.
What had been most worrying was how eloquent the wolf had gotten, considering that in his transformed state, Remus couldn't talk.
All these years of self-imposed normalcy, even tameness, all these years of lying had become undone in a few moments - a few brief, horrible, thoughtless, delicious, glorious, ecstatic moments.
Sirius moved a little and before he regained his consciousness, he screamed. Remus remembered what it was like to wake up to the sound of your own screaming.
"James is dead!" Sirius bawled. "What am I going to do, Moony?"
Sirius doesn't understand - he's got bigger problems - he needs to start covering up for himself every month, he needs to start acting like the last person anyone would suspect of being a blood thirsty, vicious predator that would not rest until it has pinned someone down, exposed their tender, pathetic human flesh, and tore it with its teeth. Like you. He always hated the way the wolf would hijack his thoughts mid-sentence.
The wolf's memories used to evoke only the hollow satisfaction of knowing no one was harmed. But now he was truly satisfied. He felt it like a warm current running through his entire body. No, Remus , the man said. Be kind, be gentle, be good.
"I know, Padfoot. I'm so sorry."
Sirius stared at him.
"My brother… my brother is dead…" he croaked. "Why? He is barely 19!"
"Sirius, you need help," Remus prodded.
"You need to take something for pain and you need to talk to Dumbledore, to see what you can -"
"Shut up about Dumbledore or I'll kill you, Moony," Sirius warned him, and he looked like he meant it.
Remus blinked.
"James would have wanted you to -"
"Don't talk to me about him!" Sirius growled. He was scary, nearly fanatical. He did not appear to give a damn about having been bitten. But of course, what would he know, to him, it has always been nothing but fun. Don't be bitter now, the human said.
"That bitch did it," Sirius said.
"James told me - she left because of Snivy. He talked her into it, that ungrateful little…"
Remus listened inattentively as Sirius talked himself into a rage.
I need Dumbledore.
The memory of his first transformation with his friends proved ineffective, as had the memory of being named prefect.
Getting my letter… they are working on a cure… he cast his Patronus to tell Dumbledore he had to meet with him.
Don't try to deny it's the real you , the wolf said, as it always had. Sirius looked at him with outrage, as though the ability to cast a Patronus at this moment was personally offensive to him.
"Got over Prongs fast, haven't we? After everything he did for you?"
"No, Padfoot. It's not like that. I'm just used to it. You'll understand in time."
"If I ever understand, kill me."
Remus could not argue with that. Sirius would never understand - Sirius never understood why James had saved Severus, he never understood why Remus was upset. He would never understand how I could cast a Patronus even though I'm sad and horrified and hopeless, but you cast them to shield against Dementors, don't you? Otherwise, what's the point?
It was fortunate for Albus that the full moon lasted three days. He had already met with Lily by the time Remus had come, he was already aware of the apparent disappearance of James Potter. When Remus came to him with a new problem, he also presented a solution.
"I have three problems, Remus," Dumbledore said patiently.
"James had disappeared without a trace, but we both know he died on a mission for the Order. He won't return. My second problem is you - the unregistered werewolf whom I have let into my school, and have covered for - no, don't thank me, your work for the order is payment enough.
My third problem is Sirius. I don't expect that he'll be content with the protections I have put in place for you, not without his friend, no matter how far my protections can extend to him."
"He doesn't understand it yet," Remus explained on behalf of his friend. "He thinks it's a joke. James used to call it my 'furry little problem.'"
Your furry little problem. So kind of him to call it that, and so ignorant. It always made Remus feel so alone, when his friends insisted he was like them, encouraged him to let loose, even, to be less of a teacher's pet and more of a wild animal like them.
Goes to show them. I never wanted to bite anyone, not even him, especially not him.
"I've covered for Sirius before, surely you remember that," Dumbledore said gently, taking Remus out of his reverie.
The wolf remembered the enticing scent of the quarry that had wandered into its cage and was snatched away from him. The man bowed his head in shame. How you fantasized about something like that happening again - to kill, and not be guilty. It's why you forgave Sirius, admit it.
"If the people at the Prophet got wind of this, what do you think they would make of it?"
Remus could not understand how that rag was relevant.
"One James Potter, gone without a trace. One werewolf everyone is going to find out about, and one Remus Lupin, whom I must continue to protect, or I won't be able to protect this school from Voldemort. Remus, we are going to tell them the story they would have come up with anyway, if left to their own devices."
Remus looked at him, puzzled.
"Sirius had been turned by an unknown werewolf and he bit, killed, and ate James Potter."
Remus could not understand how Dumbledore could have the presence of mind to make such horrible jokes.
"I'm afraid I'm not joking, Remus."
"But you can't! It's my fault!"
"No Remus, it's not. It's nobody's fault. You did what you could."
The wolf knew this was false. The wolf could smell lies. The man merely cowed under Dumbledore's gaze.
"But he'll go straight to Azkaban, and he didn't - he would never, you know him!"
"No, he wouldn't - not to James. But he did not make it his concern to protect you, and he knew how far I've gone to protect you. If his plan had worked, what do you think would have happened to you? A student disappearing on the full moon would have been impossible to explain. If you can't control him, and you can't, he will expose himself as well as you. Can I count on your cooperation?"
Remus was horrified, but he nodded, knowing he'll regret it for the rest of his life.
A cell in Azkaban was waiting to be filled. It's either him or me. And it's not so bad - Azkaban won't hold him, after all.