The dark room of the dusty closet was never as cozy as it was now. Although he wasn't cozy anywhere, not even in his own skin. He howled like a wolf, tore his own hair, and wept at the top of his lungs.
A couple of years ago, Sirius, James, Peter, and you discovered Remus's secret - he was a werewolf. You were all 14 years old when you decided to become Animagi, secretly and illegally, but what wouldn't you do for your best friend?
Time has passed, you all were already 16, and your fifth year at Hogwarts has begun, when the four of you finally became Animagi. Every month, one night was spent in the dark forest, running and playing with Remus, supporting him in such a difficult moment for him. But by the end of the year, everything fell apart. It was Sirius’ fault.
Sirius was foolish, not thinking about the consequences of his actions, but he rarely relied on logic and common sense. He did what he thought was funny, he's reckless, but it will be a lesson for him. A harsh one.
Last night, when the moon was full, Sirius lured Snape to Remus's hut for a prank, and only by a miracle and your and James's efforts did Snape escape unharmed. The foolish prank could have resulted in the death of the Slytherin, the expulsion of Remus, or even imprisonment. Remus could have not only killed Snape, but he could have infected him with lycanthropy, something he wouldn't wish on his worst enemy.
But it ended up being even worse than Snape's infection or death. You were the one who was hurt. In order to save Severus from the werewolf, you transformed into your human form, which resulted in Remus biting you.
You don't remember how you ended up in the hospital wing, but it's likely that James and Peter dragged you back to the castle. You woke up already in hospital bed, three worried pair of eyes were glued to you, waiting for you to wake up. Thanks to Madam Pomfrey's quick reaction, you weren't infected, but the risk was serious.
The marauders didn't talk to Sirius, they said ‘he committed a crime’, ‘he betrayed them’. And now, you haven't seen him among the eyes looking at you, while you winced from the pain. He hated himself more than Snape, more than his family or his former(he was sure they won’t ever forgive him) friends. He was sure that he was the last thing you wanted to see right now. Wiping tears from his cheeks, he returned to his bed, burying his head in the pillows, hoping he would suffocate.
He knew he probably should have been the first thing you saw when you woke up. He promised himself to stick by your side, no matter what. But instead, he cowardly hid upstairs in his bed like a kid, not able to face you.