20th December 1972

Peter had always known he was different from his friends. James and Sirius were always the loudest in the room, always the first to take action. Remus, though quieter, had a sharp wit that made him stand out in his own way. Peter… Peter was the one who watched. He was the one who noticed things, who remembered the details that others overlooked. And tonight, that instinct had led him to something big.

It had started with suspicion. Small things, really. Remus always vanishing once a month, coming back looking half-dead. The excuses that didn't quite add up. And then there was the secrecy—the way Madam Pomfrey would whisk him away without question, the way even James and Sirius never pressed him too hard about it.

But Peter wasn't like them. He needed to know.

Peter had learned long ago that the best way to keep up with James and Sirius was to be quiet, unnoticed, and quick. He wasn't as fast as James on a broom or as smart as Sirius when it came to breaking the rules, but what he did have was patience. And patience had led him here—trailing Remus for the second time in as many months, watching as their friend slipped away yet again.

He followed at a distance, sticking to the shadows, his breath shallow as Remus turned a corner near the Hospital Wing. Peter hesitated, flattening himself against the wall, heart pounding. He had seen this before—Remus disappearing through that door near the Hospital Wing, the one that never seemed to be there during the day, always locking behind him.

But this time, Peter had come prepared.

Twig twitched in his pocket as if sensing Peter's hesitation. Peter absentmindedly stroked the Bowtruckle's head before pressing himself closer to the door, listening. He crouched low, letting Twig do his thing and with a faint click, the door creaked open.

Peter barely had time to think before slipping through.

On the other side, the corridor was dimly lit by torches, leading toward a back entrance. He hurried forward, careful to stay just out of sight, until he saw them—Remus and Madam Pomfrey, stepping out into the cold night air. Peter ducked behind a suit of armor as the door swung shut behind them, waiting until their footsteps had faded before pushing it open and following.

The Hogwarts grounds stretched wide and quiet before him. Remus and Pomfrey moved quickly, their figures dark silhouettes against the moonlit landscape. Peter trailed behind, half-running, half-stumbling over frozen patches of grass, his breath visible in the chilly air.

They were heading straight for the Whomping Willow.

Peter stopped a few yards away, heart hammering as he watched Pomfrey throw something at a knot in the roots. The massive tree, usually wild and thrashing, suddenly froze. Its deadly branches stilled, like a beast put to sleep.

Then, to Peter's shock, Remus crouched and disappeared into a gap between the roots. Madam Pomfrey followed without hesitation, vanishing beneath the earth.

Peter remained frozen in place, his lungs burning from the cold night air. His hands clenched into fists at his sides. What is this? Where are they going?

Then, as if drawn by some unseen force, his gaze flicked upward.

The full moon was rising, glowing silver and high above the castle, casting eerie light over the grounds.

Something inside Peter clicked.

His breath caught, his mind racing back through every moment—Remus disappearing every month, the exhaustion, the injuries, the secrecy. The way he always returned looking half-dead, as if he'd been in a battle no one else had witnessed.

Heart still racing, he turned on his heel and rushed back toward the castle, barely aware of the frozen ground crunching beneath his feet. By the time he reached Gryffindor Tower, his fingers were numb, and his thoughts were a tangled mess.

He climbed through the portrait hole and hurried up to the dormitory, not even sparing a glance at James and Sirius, who were playing a quiet game of Exploding Snap near the fire. He rummaged through his trunk, tossing aside old textbooks and bits of parchment until his fingers closed around the worn edges of his lunar cycle chart from Astronomy class.

Peter sat on his bed, spreading the chart out in front of him, his breath shallow as he scanned the dates. He traced his finger over the cycles, matching them against the moments when Remus had vanished and when he had come back looking worse for wear. His stomach twisted as he checked again, and again, willing the pattern to be a coincidence.

It wasn't.

Every full moon.

Peter swallowed hard, his hands gripping the edges of the parchment. Remus is a werewolf.

His chest tightened, and a strange mix of fear and fascination crawled under his skin. He had uncovered something huge, something that even James and Sirius didn't know. For once, he had the upper hand.

He had a choice now—tell them what he had figured out, or keep it to himself. Peter sat there for a long moment, staring at the moon chart, feeling the weight of the secret settle onto his shoulders.

…

Peter barely slept that night. The dormitory was dark and still, except for the soft, steady breaths of his sleeping friends. James sprawled out on his bed, his blankets twisted around him, while Sirius slept in his usual way—one arm thrown over his face as if blocking out the world. Remus' bed was empty, and that fact alone made Peter's stomach twist uncomfortably.

He sat upright, the moon chart still clutched in his hands. His mind was racing. He should tell James and Sirius. They deserved to know. But something held him back.

Peter had always been the one who followed. But now, he had information that they didn't. Something important. Something powerful.

His gaze flickered over to James, who let out a soft snore, then to Sirius, who shifted slightly in his sleep. Would they believe him? Or would they brush it off, tell him he was mistaken, that there was no way their friend was a werewolf? James was trusting to a fault, and Sirius—well, Sirius had a habit of laughing off anything that wasn't an immediate problem. If Peter told them, would they even take him seriously?

But what if they did believe him? Would it change everything? Would they start looking at Remus differently? Would he?

He swallowed hard and shoved the moon chart under his pillow, lying back and staring at the ceiling. His heart pounded, and a hundred possibilities rushed through his mind. What if Remus lost control one night? What if Pomfrey wasn't there to stop him? The thought sent a shiver down his spine.

But another part of him—the smaller, quieter part—thought back to Remus himself. The way he laughed with them, the way he always helped Peter when he struggled with homework, the way he never, not once, had given Peter a reason to fear him.

Morning came too quickly, and Peter barely touched his breakfast. His mind was too preoccupied, his hands fidgeting with the hem of his robes. James and Sirius were loud as always, talking about the upcoming Gryffindor versus Ravenclaw match, but Peter barely heard them.

When Remus finally appeared at breakfast, looking as exhausted as ever but forcing a small smile as he sat down beside them, Peter nearly choked on his pumpkin juice.

"Morning, lads," Remus said, voice hoarse.

James nudged him playfully. "You look like hell, Moony. What'd Pomfrey do to you this time? Lock you in a cupboard?"

Remus gave a weak chuckle. "Something like that."

Peter felt his pulse quicken. It was a joke. A joke that James had made a dozen times before. But now, knowing the truth, the words sat differently in Peter's chest.

Peter forced himself to laugh along with the others, but his stomach felt hollow. His fingers twitched toward the pocket where he had stashed his moon chart, itching to pull it out, to press Remus for answers, to do something with what he knew.