I'd like to thank my wonderful beta, Natasha Johnson, for helping me enormously with this story! Plus: this story is a bit AU, because Sirius was already Secret Keeper when he switched with Peter, but in Canon he was never Secret Keeper.

***

Peter tried to smile with Sirius and James as they laughed. They were always laughing, but always at him; never with him. Remus was sitting by them, the corners of his mouth lifting to form a reluctant smile. They had won him over too.

“With that nose of yours, Peter, you could easily pass for a rat.�

“Wet your pants, did you Peter?

“You’re so damn thick, Peter.�

It was endless, the teasing. Their merciless laughter rang in his ears like church bells. Peter used to love his three friends – now, he wasn’t so sure. Remus never incited anything; he simply laughed along with Sirius’s ridicule. Wimp – looks like a rat – can’t think for himself. This was what Sirius proclaimed was humorous, the wounding of another person. Then again, Peter had easily laughed when they had lifted Severus Snape into the air, and flipped him over to cruelly display his shorts. Peter hadn’t been bothered then. He hadn’t been the victim. Now it seemed Sirius and James needed a new person to victimize and laugh at, someone who couldn’t stand up to them. That person happened to be Peter.

Their mockery occasionally made Peter’s face swell and redden, at which point Sirius and James would relent for a while. They were oblivious to their supposed best friend’s pain and humiliation. They didn’t care who they hurt while they had fun, didn’t care at whose expense they laughed.

If it had been a remark once or twice, Peter wouldn’t have thought twice about it. In fact, he would have accepted it as familiar teasing between good friends. But when it was done every hour of every day, and in front of people other than Remus, it became hurtful and unacceptable.

Peter was tired of it. He sought vengeance. He wanted Sirius and James to hurt, like they constantly made him hurt. Especially Sirius. He was the one that always started everything, the one that began the banter.

***

For unknown reasons, Lily Evans, the girl of James’s dreams, had finally agreed to go out with him in seventh year. They got married, and had a baby boy named Harry. The wedding had been another factor in increasing Peter’s hate for his friends. Sirius had been the best man. That hadn’t bothered Peter much, since Sirius was after all closer to the groom than anyone else.

What bothered Peter was the way he was ignored. He had watched from afar as Sirius and Remus lifted James into the air. They had completely ignored him. No one had invited him to join the festivities at all. He had felt the inevitable then: he was becoming separate from his friends. He had never been one of them anyway. He knew the talk. He heard what students and staff whispered to each other when the foursome was in school.

“Look at him – following them like a loyal puppy dog.�

“He’s always looking at them like he worships them.�

“Why can’t he stand up for himself once in a while?�

“He needs to start thinking for himself.�

“They don’t even like him – they only want someone to adore them.�

Yet Peter had stayed with his friends, had not changed their relationship at all. It was the wedding that drove him over the edge. Their negligence hurt him more than any of their words had.

After Harry was born, Lily and James became aware of the danger their child was in. They went into hiding, and no one knew their location except Sirius, who had been named their Secret Keeper. Peter had seen this as somewhat of a betrayal. Again, just like during the wedding, the thought that Sirius was simply closer to James conflicted with his jealously. Didn’t he, Peter, deserve to be trusted? The thought that Remus had also not been “chosen� didn’t come into his mind but for a moment, and Peter had quickly pushed it away. He was intent on despising Sirius and James. He wouldn’t allow anything to allay his hate.

It was at that time that Peter went to He-Who-Must-Not-Be-Named and offered his help. Although revenge was high on his list, he was aware of what happened to those who stood against this Dark wizard. He had heard about the torture and the killings. Peter had never been the bravest of the brave – but he was clever when it came down to it, and knew what was best for himself.

He explained his plan to the Dark Lord, and he had agreed, for it was in his best interest to agree. Peter at that time seemed to be driven by pure hate. No happy memories came to Peter of the foursome’s time together. Only memories of cruel taunting and hurt. It fed his hate as it continued to grow to immeasurable size. He asked to see James from the one person who knew his location: Sirius.

A meeting was arranged as discreetly as possible. Peter had asked for it to be private, and although Sirius had crinkled his forehead in suspicion at that condition, he agreed.

Faced with James and not Sirius, Peter’s hatred was in danger of decreasing, so he made things quick.

He put on his face a mask of despair, and spoke with as much sorrow as he could muster. “James,� said Peter tearfully. “I feel like I’m no longer one of you. Like I’m separate.�

James frowned. “What do you mean?�

“Do you no longer trust me?� Peter asked. “Do you no longer want me as a friend?�

“Peter, how could you say that?� James sounded surprised.

“Sirius was your best man, and now you trust him with your life. Where does that put me?�

“I never thought you would want the responsibility,� said James thoughtfully.

“James, you’re my best friend,� said Peter thickly. He hoped James was fooled. “Of course I would protect you with my life. How could you think otherwise?�

“Is this why you’ve been so distant?� James said, his wide eyes conveying realization. “You think we’re cutting you out of our lives?�

“That’s certainly what it seems to be.� Peter congratulated himself for sounding like he was on the verge of tears.

“Peter, that’s not what it is at all. If I’d known that’s how you felt…� James paused.

Peter didn’t give him a chance to continue. “My being Secret Keeper would, in the end, keep you safer. It’s for your benefit.�

James looked puzzled. “How so?�

“No one would expect someone like me to be given such an important job,� Peter explained. “Your secret would be hidden even more.�

James smiled, his eyes shining. “Would you like the duty of being Secret Keeper, Peter?�

It took pure willpower for Peter not to give an ecstatic scream of joy. “I’d like that very much,� he sniffled. James smiled, and Peter sincerely returned the gesture.

The proper spells were performed to switch the role from Sirius to Peter. He didn’t hesitate to inform the Dark Lord of his information. Peter could see it now – himself as the Dark Lord’s right hand man, with power and status to call his own. No one would dare talk down to him again.

The Dark Lord, on Peter’s information, went to the Potters’ house. However, he didn’t make it out.

Before Peter learned about the blunder that happened at Godric’s Hollow, he wanted to dance in joy. James would die, and sorrow would get the better of Sirius. Then Peter would hunt him down, but his death would not be as easy and quick as James’s had been. Peter would make him suffer, make him grovel and beg.

Unfortunately for Peter, these ambitions were not to be realized. The Dark Lord killed Lily and James, but was somehow unable to kill their son, his intended target.

He fell that night, the Dark Lord, and as soon as Peter heard the news, he felt his haven crumble. Without the Dark Lord, the other Death Eaters would surely want to kill him, for they knew it was on Peter’s information that he had went to the Potters’. If the Dark Lord came back, even he might be convinced that Peter needed punishment. Peter knew what he must do. He needed to disappear from the world. But he was adamant — he would not go without inflicting pain on Sirius.

He planned it all, and step by step, he went through with it. He cornered Sirius in a Muggle street. They shouted, and in a flash, Peter cut off his finger and created an explosion. He transformed into his Animagus form, a rat, and watched as Ministry executives took Sirius away. He laughed as he scampered away on his rat paws.

He was dead to the world now. He was safe. James was dead, and Sirius would go to Azkaban. From the start, Peter had hoped things would play out this way. Now his work was done.