CONTEXT
Ron is actually a time traveling Dumbledore. Dumbledore is a time traveling Ron...
Ron looked at the boy sitting across the carriage from him. 'Are you really Harry Potter?' he blurted. Meow.
Of course Ron knew who he was. As the boy pulled back his fringe to show his cat-shaped scar, Ron's mind drifted back to just under ten years ago when he had seen it for the first time as he deposited the baby Harry on his aunt and uncle's doorstep. Harry could never know. Going to Hogwarts was going to be more complicated than Ronbledore had thought!
Quickly, he nodded and made the appropriate awe-stricken noises signalling he was new to the scar debacle. Meow.
Thankfully, before Harry twigged, a bushy-haired youth knocked on the door. Meow.
Thankfully the Muggle-born girl, Hermione Granger, was talking to Harry and providing a distraction from Ron's complicated facial expressions that came with being a time travelling wizard. This distraction allowed Ron to take a quick swig of the Polyjuice Potion that kept him in the form of a handsome, red-headed schoolboy.
Sirius Black was sitting in Azkaban. Alone. In the dark. Transformed as Padfoot. He would get his revenge. Meow.
He'd been plotting for some time, but the likelihood of Peter Pettigrew visiting him in prison, transforming back into a wizard in front of the Dementors and exposing himself for the fraud he was, Sirius reflected, was becoming increasingly unlikely. And that didn't even allow for the Dementors not actually caring. No. He had to act now.
After giving it some thought however, Black realised that his station in life wasn't all bad. After all, not every prisoner has fur and a tail, and if one must spend undeserved time in Azkaban, doing so as a dog must be the most convenient way.
He had a weird feeling that he would escape in another two and a bit years anyway, so the remaining time must be spent perfecting his ability to confuse everyone who only catches a glimpse of him out of the corner of their eye by transforming into his other form.
He also had frequent dreams about the dreaded Whomping Willow. Little did he know, the future held a sweet sweet piece of dream-related revenge - biting sneaky Ronbledore and preventing him from time-traveling. Again. Well, at least for a short while.
Hermione Granger was very nervous. Perhaps if the other witches and wizards found out that her parents were dentists she'd be ridiculed. Of course, what they didn't know, is that her parents weren't dentists at all. They were in fact Muggle spies who were responsible for keeping the Prime Minister up to date with the goings on in the Magical world. Hermione had been turned into a witch by drinking a special potion with her porridge one morning when she was very young. She was, in fact, their opportunity to infiltrate the magical world. Little did the Grangers know that the greatest wizard in the land, Dumbledore, was on to them. In fact, he had been since the start. But as Dumbledore knew, all great plans take at least 18 years to come to fruition.
Transformed into Padfoot, Sirius found he could move around without the Dementors seeing him. In the next cell Cutthroat Clive's unicorn had come to visit with a backpack full of birthday cake to celebrate Clive's 40th birthday. Clive was a nice enough guy, he'd just fallen in with a bad crowd in the 'pirating on the high seas' scene. His unicorn always brought him fruitcake for his birthday every year, and he never managed to tell her that no one likes fruitcake, because he didn't want ot hurt her feelings. While Clive's unicorn was cutting up the cake, Padfood padded into the open backpack on the floor and lay down in the bag. Clive's unicorn would be able to carry him straight out of the prison and back into the free world.
Little did he know that this year the cake had a surprise in it...
Clive's mother, Suzanne, was a lovely old lady working at AzkaLab, a small potions laboratory which developed new tools to help the Aurors catch criminals and send them to Azkaban. Being supported by the ministry of magic, AzkaLab received regular visits from Ministry Workers. This year, the visitor was Arthur Weasley.
After Dumbleron's first time travels, Arthur started noticing changes in his youngest son's personality and decided it was time for some parental actions. He set his mind to get his son back to normal and went off to seek a furry pet to cheer him up. Of course, everybody knows the Weasleys aren't a wealthy family... which led Arthur to the nearest pet shelter on his way to AzkaLab. There, a fat grey rat with a missing finger caught his attention.