Sirius Black was the only one still in the Gryffindor common room, due to the fact that it was well after midnight. He sat slumped in one of the red armchairs, his head leaning on his hand. A large, heavy book was positioned on his lap, and his gray eyes, drifting shut and partly covered by a tuft of hair, were scanning its text. Suddenly those eyes snapped open wider and he sat up, a startled look on his face.

"Oh… my… God." He jumped out of the chair, heaving the book with him, and raced up the nearby staircase to his dormitory.

"James! Peter! Wake up, wake up, wake up!" Sirius stopped at his best friend, James's bed, and shook the boy inside.

"Sirius!" exclaimed James, sitting up with a gasp. "What the hell is wrong with you? It's-it's…" He grabbed his glasses from a bedside table and glanced at the clock there. "Three in the morning!"

"It doesn't matter!" said Sirius wildly. "It's Remus – his mom isn't sick!"

James scratched the side of his face. "So… that's good, I guess, but why'd you have to wake me up for it?" Peter came scuttling over from across the room to see what the commotion was about.

"Because," continued Sirius. "His mom isn't sick. Neither was his uncle. His cousin never got married. None of that ever happened."

James shook his head. "I have no idea what you're going on about. I'm going back to bed." He started to lie down again, but Sirius grabbed his shoulder.

"This is important."

"What? What is important?"

Sirius took a deep breath. "Remus is a werewolf."

There was a moment of stunned silence. Then James started laughing, and Peter followed suit.

"No- No, guys, I'm serious!" cried Sirius, so determined that he didn't even bother to make his usual serious Sirius joke.

James eyed his friend's face, which for once was not at all comical. "Yeah, nice try, Sir. Can we go back to bed now?"

"No, you can't! Hear me out. I honestly think you should listen to me right now."

James sighed and looked over at Peter, who was watching the conversation intently. "Fine, whatever, say what you want."

Sirius nodded. "Remus… he leaves all the time to go back home. But I don't think he really goes home. Have you noticed that it's once a month that he leaves? Once a month, during the full moon."

James squinted as if thinking hard. "It's not… it's not always during the full moon. How would you know that for sure?"

"I… Check your lunar chart. It was a full moon yesterday, when he left. And last time it was, too. I don't know the dates for the times before then, but just trust me on this."

"Trust you?" barked James. "You're telling me one of my best friends is a werewolf with barely any solid proof, and you want me to just trust you?"

"Yeah, I do!" Sirius retorted. "Because… because what if I'm right?"

A second blanket of silence covered the room as the three boys thought about that very question. Then-

"Well, we could always ask him," suggested Peter.