Tell Him I'm Waiting
He wasn't sure how he'd managed to sneak into the building, Dumbledore had lowered his protections apparently. There were more posters inside the walls of Hogwarts but Sirius didn't care.
Padfoot had been skipping round the school for a good while before he came to the great hall. He paused outside the door, smelling the delicious feast through the door. He heard Dumbledore's large booming voice echoing round the hall as he did his usual welcomes.
"And I'd like to introduce our new teachers," Padfoot was about to continue but froze when he heard Dumbledore announce, "Professor Lupin has come to teach defence against the dark arts for a short time."
Without thinking Padfoot nudged the door open a crack to find Remus standing as the hall applauded. He was older, had more scars but he was definitely still Remus. Moony. His Moony. His Moony who was staring right back at him, eyes wide, mouth slightly parted, Padfoot's tail went mad with excitement until he saw the short flicking of Remus's wrist, telling him to go. He didn't want to. He wanted to stay with his Moony but Moony was always smart and knew what to do. Padfoot backed up only to hear Dumbledore announce that dementors where coming to watch over Hogwarts in search of Sirius Black.
"Well shit." He thought.
Turns out the dementors couldn't find him as Padfoot at all. He tried to keep his head down and find Moony or Harry, he knew if he was spotted by anyone else he would be kicked out, Padfoot or not, dogs weren't aloud at Hogwarts.
He couldn't help it though, being back in Hogwarts made him want to prank people so it was entirely not his fault when he turned into Sirius in front of the Fat Lady, he'd just transformed for a millisecond and she'd already screamed, Padfoot had turned back and ran off.
Whispers of 'A dog in the school.' and, even worse, 'Sirius Black in the school.' where starting to gain popularity. Padfoot tried to keep his head down but was unsuccessful. He tried to find Moony or Harry, but he kept getting old scents of James in passages that hadn't been discovered since they had been there.
Then there was the fact that he was pretty sure Remus didn't want to be found, he was scattering his scent all over the castle, walking everywhere. It was infuriating.
Day's had passed. Or was it months? Or years? When he caught a sent of Peter Pettigrew. He'd at first assumed it was an old scent, like James's, but upon approaching it he realised not only was it a moving scent, it wasn't exactly like Peter, it was more like... Wormtail.
Anger flared up inside him, he chased the scent for miles, up and down stairs, into classrooms and out again. The rat was going everywhere. When suddenly he caught up to the scent. It was beside a boy with flaming red hair. and Harry! And some other girl but that didn't matter.
The boy was on the floor, Peter in his hand, the girl and Harry stood closer to Padfoot,
"Harry, you do realise what tree this is?" The girl said as the red haired boy came to a stop beside the womping willow.
"Oh that's not good," Harry breathed, he sounded like James, James! A mini-James!
"Ron! Run!"
The red haired boy or, as Harry had called him, Ron, looked up. But he didn't seem to notice Harry and the girl as his eyes looked on Padfoot, Peter saw him too, Padfoot growled,
Nasty. Stinky. Ugly. Rat!
"Harry, Hermione run!" Ron said pointing to Padfoot, his voice screechy with fear.
"It's the grim!" Ron said, but Padfoot wasn't listening, he was staring right at Peter, he growled deeper before charging at them, barking, he jumped over Harry and Hermione and straight for Ron. And Peter.
He grabbed the boy by the leg dragging him backwards along the grass to the tree, Harry and Hermione followed, yelling for Ron but Padfoot wasn't listening he was angry he was going to tare Wormtail to shreds and send him to the pits of hell where he could burn.
He pulled the boy down into the willow, Harry got onto his stomach trying to snatch the boy back but Padfoot was quicker, dragging Ron into the tunnel to the shrieking shack.
He glanced up just in time to see a branch smacking Harry and the girl away from the entrance.
He dragged the boy all the way through the tunnel until they emerged in the main room of the shack.
Padfoot took a minute, overcome with memories of sneaking in here under the cloak, hearing Moony's screams as his bones reformed, it made him want to scream just the thought of it.
When Harry and Hermione got into the shack, Sirius was already back in human form, he had been pacing, debating the most painful way to kill Wormtail, when Harry and Hermione ran up the stairs they opened the door leaving him hidden behind it.
"Harry! It's a trap, he's the dog, he's and Animagus!" Ron said pointing to Sirius who pushed the door aside.
He thought he must look awful, hair a mess, still wearing Azkaban prison clothes, tattoo's showing, wearing an old jacket he found in the dump, but he didn't care, he needed to kill Wormtail, then he'd prove he was innocent. Any Moony would be here soon. Moony always knew where to find him, Moony would find him soon.
Soon, very soon, Moony would meet them. But for now he had to face three children who all thought he was a murderer. Soon, he would be a murderer but he didn't care, he would killer Peter if it was the last thing he did.
He walked slowly approaching the three of them, trying his best not to be scary, but his eyes where focused, he had to remind himself to blink. Maybe he was mad. But it would be okay when Moony got here. Everything would be okay with Moony.
First, he had to kill Peter.
"If you want to kill Harry you'll have to kill us too!" The girl said stepping in front of Harry, very defiant, like Lily. Sirius thought. He liked her.
"No!" He breathed, voice hoarse from lack of use "Only one will die tonight!"
"Then it'll be you!" Harry screamed charging at Sirius who had, admittedly, not expected this. Harry grabbed him by the neck, he was strong, like James. And Sirius was weak and confused, he let Harry drag him to the ground with little to no resistance.
Harry pulled out his wand pointing it at Sirius, one hand still on his neck, Sirius gasped, he was so tired and Harry looked like James. They used to paly fight, Sirius and James, and James would get his wand out, never to fire, simply to prove he had won. He often won.
But Harry was angry Harry wanted to kill him, but it would be okay, Remus would be here soon. Wouldn't he? He was taking a while. Bit he always found Sirius. Didn't he? Maybe he didn't want to.
Please come Moony. I'm waiting.