James was dead. Sirius was dead. Remus will hopefully survive this second wizard war but it wasn't looking good.
And it was all Peter's fault.
The guilt had been eating at him ever since he had told the Dark Lord where the Potters were, so much so that he just blocked himself off from them and the others. They just thought he was hiding from the Dark Lord. But then afterwards, when Sirius realized what had happened and chased after him, the guilt increased tenfold.
"You were a Marauder! We were you best friends!"
The guilt died down after he turned into a rat and lived with the Weasleys. It wasn't in any of the books they read when they were working on the transformations, though he guessed nobody ever tested it, but if you stay in your animal form for a long period of time, the animal instinct begins to take over. So by the time Sirius broke out of Azkaban, he wasn't thinking about his past. He was thinking about when his next meal was and where a good place for him to a nap. But the news of Sirius braking out and saying "He's at Hogwarts... He's at Hogwarts..." didn't do well for him. Everybody thought the black haired man meant James's son, Harry Potter, but he knew better. He knew his old friend was coming to get him, and his human mind broke out of his daze with guilt following.
Now he has been directly responsible for the return of the Dark Lord. There was no turning back to the side of light. He was done for until he died, which he will. He knew that his side wouldn't win and whether it was one of the good guys killed him or the Dark Lord, he will be dead in the next few years.
As it was he was trying to distract himself, and in the last ditch effort to not think about the war, he went to go see Snape. Peter was standing by the door of the dungeons, watching the potion master stir a lime green potion. He had no idea what it was but, then again, he was never good at Potions.
Snape stopped stirring and glanced at him, his default glaring expression on. "Is there a reason you're watching me, Pettigrew?"
Peter flinched at the glare but answered anyway. He refused to be afraid of someone they used to play pranks on. "I-I got bored..."
"You got bored." Snape sneered but turned back to the potion anyway. "Just don't get in my way." He stirred counterclockwise for a few moments; the clicking of the stirrer hitting the side of the cauldron was the only noise in the room. Soon, with the potion being dark green, Snape reached backwards to the shelf behind him, without looking, and started to feel for something, staring intently at the potion. Obviously he didn't find what he was looking for as he turned to look after a moment. He scowled as his eyes scanned over the contents of the shelf, only in which half could be identified by Peter.
"Don't touch anything Pettigrew. If I didn't have to get this done as soon as possible, I wouldn't leave you in here." Snape then left the room with those words and a swish of his cloak, making a bat appear in Peter's minds eye.
Peter shook his head to get rid of the image and looked at the potion. He couldn't really see it, other then the color, as he was shorter then Snape so the table was just a few inches too high to truly see the cauldron. But curiosity got the better of him and he was soon standing on his tip toes to see what the potion was. Now that he could see, he could tell that the dark green was slowly turning back to lime green. Of course, his luck kicked in and he lost his footing, bumping into the table. Luckily the cauldron was fine but the table knocked into the wall, causing a potion in a vile to fall from a shelf above and into the cauldron.
Peter panicked. He just ruined the formidable(read: freaking scary) Potion Master potion, and the blond had a sinking feeling it was for the Dark Lord. He jumped when he heard the tell tell footsteps of Snape coming down the steps and grabbed the now empty potion vile and cork out of the cauldron, now the same lime green color thankfully, and threw them into the corner before running back to the doorframe. He just got calm down by the time Snape came back in.
Snape raised an eyebrow, probably noticing something was wrong, before going over to the cauldron and dropping in whatever ingredient he got. The potion slowly turned from a lime green to bright purple. Snape blinked then glared at Peter, who flinched back.
"What did you do?"
"W-what makes you think I did something?" Peter pressed himself against the wall as Snape came closer.
"It's supposed to turn form green to black, not purple. Now. What. Did. You. Do?"
Peter was saved from answering, though he didn't think what happened was good thing at the time. The potion started shooting off sparks and glowing brighter purple. Snape noticed and slowly backed to the wall next to Peter. The blond looked at him.
"W-what is it doing?"
"Either it's just shooting off extra energy," Snape shook his head and scowled. "Or it'll take it a step farther and explode. Just hope that it'll won't be a big explosion if that happens."
Of course, the potion took the second option, probably just to prove Snape right and mess with them at the same time, and the two death eaters knew no more.