The House Competition:
House: Slytherin
Category: Short
Prompt: Breaking somebody's trust [Theme]
Word Count: 1030

It was inevitable that he'd break someone's trust. After all, his animagus was a rat, and rats were filthy, foul creatures which lurked in the shadows. Lily and James and Sirius really should have known better than to trust him. And yet they did.

It had all begun in his sixth year, when he'd been sick of all the fear and terror and jealous of how James, Sirius, and Remus were adored and he, their little sidekick, was forgotten.

He'd searched out Severus Snape. "Please," he'd said, "Take me to your Master."

Snape whipped out his wand. "I don't know what you're talking about," he'd stated, deadly calm. "Now leave."

"No! You know who I mean!" Peter whispered, looking up at the taller boy with watery eyes. "I've seen your Mark. Please!"

In a flash, Snape had him pinned to the wall, his wand digging into Peter's neck. "How?" he spat. "Were you spying on me?"

"I— I—"

"Answer me!" Snape roared.

"I'm a rat animagus!" Peter cried desperately. "I crept into the Slytherin dorms and saw it!"

Snape's eyes flashed. "You tell anyone that I am Marked, and I will have you thrown into Azkaban for being an unregistered Animagus."

Peter nodded, stammering, "I— I— I understand."

Snape let him fall to the floor. "Follow me," he spat. "I'll take you to our meeting. But you may not meet the Dark Lord until you have earned his trust."

After that day, Peter was a double agent. He relayed information to the Death Eaters, ignoring how his conscience twinged. With each tidbit of information, he was slowly betraying his friends. They trusted him. They confided in him. Yet he was sharing that information with their enemies.

However, he didn't let that bother him for too long. He was a rat; this was what he did. And he wasn't really hurting them. So what if their pranks weren't as successful? So what if some woman Peter had never met died because he'd shared how she was secretly helping the Order? It didn't matter that much in the long run.

Peter told himself this through the years, from after he'd graduated from Hogwarts to when he was working for the Order full-time. But then, one day, everything changed. Dumbledore shared Harry's role in the prophecy with him, Sirius, Lily and James. The Headmaster arrived unannounced one night as the four were having a small get-together to say, "Your son will defeat the Dark Lord."

"What?" Lily cried, holding Harry tighter to her. "He's a newborn! How?"

"That is not for us to know." Dumbledore gazed over his half-moon spectacles at her, then his gaze swung to encompass James, Sirius, and Peter as well. "But a prophecy said he would, so we must keep him safe."

Lily nodded. "But how?" she asked, her voice trembling. "So many safe houses have been compromised already."

"The Fidelius Charm," Dumbledore answered. "It's old and powerful magic; it shall keep you, your family, and your location secret. You only need someone you can trust to never give away that secret — a Secret Keeper."

"So I need to find a Secret Keeper," James stated. "Someone I trust with my family's life."

"Yes. Here are the instructions. Lily can cast it. I will leave you to it." With that, Dumbledore swept out of the Potter's cottage.

After Dumbledore had left, James turned to Sirius. "Sirius, can you?"

Sirius ran a hand through his hair. "I'd love to, mate, but—"

"But what?" James interrupted.

"But I think Peter would be better."

What? Peter thought. Him, better than Sirius? They trusted him that much?

"Everyone knows it would be me," Sirius continued. "They'd hunt me down— but who would think you chose him? I could be the decoy."

To Peter's surprise, James nodded. "You're right, Sirius. Peter, would you be our Secret Keeper?"

Peter nodded, his mouth dry. He would do this. He could do this. They trusted him to keep them safe from the Dark Lord, and keep them safe he would.

Yet only months later he realised that he couldn't. Not anymore. He was too weak to keep their trust. He was too weak to keep them safe. Once, he'd loved the Potters. Once, he'd have done anything for them. Once, long ago, he'd been a true Gryffindor; however, that had been before he'd joined the Dark Lord. Now, a full-fledged Death Eater, he sat in his friends' home, munching on their biscuits, sipping their tea, and planning to betray them.

He glanced about the room, taking in James's exuberant grin, Sirius's silly smirk, Remus's exasperated eyeroll, and Lily's doting smile. Then, Peter's gaze swung to Harry.

From his crib, Harry began to wail, and Peter looked down at the crying infant in disgust. Harry. If it weren't for Harry, the Dark Lord wouldn't have taken a special interest in the Potters. If it weren't for Harry, the Dark Lord wouldn't have insisted Peter give him the Potter's location. If it weren't for Harry, Peter wouldn't have to choose between his friends and his life.

He'd miss Sirius, Remus, and James the most. They were the first of Hogwarts to accept him; they were like his brothers. But he was still going to betray them. As much as he loved them, he loved living more.

"You liar!" Sirius shouted. "You filthy traitor! You— you little rat!"

Pettigrew chuckled nervously, stealthily drawing his wand as he said, "Don't try to pin it on me, Sirius!"

Sirius advanced on him, murderous rage in his eyes, and Peter knew it was time to go. "You were the Secret Keeper— you were the one who betrayed Lily and James!" he shrieked. With that ringing accusation, Peter cast a quick diffindo on his finger, a bombarda maxima on the street, and then transformed into a rat and crept into the sewer.

James may truly be dead, but Sirius was as good as dead to him now. He'd betrayed James's trust and now Sirius's — of the Marauders, only Lupin remained, and Lupin had never trusted him anyways.

He really was alone now.