Disclaimer: Harry Potter belongs to J.K. Rowling and I take no credit for her work. Excerpts from her books are included periodically to keep this fanfic somewhat close to canon. I own nothing.

Regulus Arcturus Black slinked his way down the Hogwarts corridor. Honestly, how could he have lost Pettigrew? Regulus hadn't expected that the rat's fat little body could have moved with the speed that it had. He had lost Pettigrew on the train, only to find a trail of his scent at Hogwarts, and then lost it again. It was difficult for Regulus to comprehend all that had happened that day.

It began as it usual. He was hunched in his cage and his body ached. He was fed something that he assumed had once been fish. And then there was a shadow. Chocolate brown eyes stared at him. They were framed by thick, dark lashes and turned amber when the light hit them. They held a softness and warmth to them that nobody had looked at him with in years.

And then she extended her hand to him.

Call it kneazle intuition or maybe even his loneliness, but in that moment, he completely trusted her. He heard the girl's friend and the saleswoman attempt to dissuade her from buying him, and yet she unlocked his cage and held him in her arms as if he was an old friend. Regulus understood why they discouraged her from purchasing him. He was pretty ugly and had a record. He was one bite and scratch away from being thrown into the streets.

The girl was soft, warm, and smelled like home. Like coconuts, brown sugar, and…Sirius? How in the hell?

Regulus peaked through the girl's mass of mahogany curls that he was nuzzled in. Over her shoulder stood a teen boy barely concealing his disgust. He had seen that exact same expression on only one other face before: James Potter. Putting together the few puzzle pieces that Regulus was given, he was certain of three things: 1. This boy was Harry Potter. 2. Sirius was in contact with these two kids. 3. Regulus really wanted this girl to adopt him.

And she did.

Running into Lupin and Pettigrew definitely was not what he had on his agenda for the day, either. He couldn't believe that Pettigrew had spent the last decade in his Animagus form…Regulus had felt so clever living as a cat. He had fooled everyone and faked his own death. He was essentially a fly on the wall in the Wizarding World. Yet here was Peter fucking Pettigrew who apparently had the exact same survival plan as he did.

However, Pettigrew was now in dire need to find a new plan. Now that Regulus found him, what made him think that he was going to get away? Sirius was a lot of things, but he was never a traitor. Regulus never believed for one second that his brother would have betrayed the Potters. Pettigrew, though? Of course. Regulus never had definitive proof that Pettigrew was a Death Eater, but he did distinctly remember seeing a robed 5'6" Death Eater who tripped over the hem of his robes a lot. That was evidence enough that it had been Pettigrew.

While Regulus prided himself for being one of the more mentally sound Blacks, he felt crazed. Bloodthirsty, even. Pettigrew was going to be sent to Azkaban, but only after Regulus played with his food.

Pettigrew was going to suffer.

Regulus decided that the best way to potentially learn more about Sirius and Pettigrew would be by following his little human around. He followed her everywhere. It was purely for investigative reasons, not because she was incredibly kind to him and smelled at
all.

He lounged on her lap during breakfast, accepting the pieces of meat that she fed him. It was wonderful.

Hermione examined her new schedule. "Ooh, good, we're starting some new subjects today," she said happily.

"Hermione," said the ginger boy with big ears who Regulus assumed was Weasley #2,000. There were so many Weasleys.

"They've messed up your schedule. Look—they've got you down for about ten subjects a day. There isn't enough time," The boy continued.

"I'll manage, Ron. I've fixed it all with Professor McGonagall."

"But look," said Ron, laughing, "see this morning? Nine o'clock, Divination. And underneath, nine o'clock, Muggle Studies. And"—Ron leaned closer to the schedule, disbelieving—"look—underneath that, Arithmancy, nine o'clock. I mean, I know you're good, Hermione, but no one's that good. How're you supposed to be in three classes at once?"

"Don't be silly," said Hermione shortly. "Of course, I won't be in three classes at once."

"Well, then—"

"Pass the marmalade," said Hermione.

"But—"

"Oh, Ron, what's it to you if my schedule's a bit full?" Hermione snapped. "I told you, I've fixed it all with Professor McGonagall."

She leaned over the table grab the marmalade. Regulus caught the glint of metal around her neck and followed it to the strange shape protruding under her sweater.

No fucking way. McGonagall gave one of her students a Time-Turner? This was a whole new level of Gryffindor recklessness.

Hermione hurried her way through breakfast before slinging her satchel over her shoulder. Regulus followed her to the North Tower for Divination. Last time Regulus remembered, the class was an absolute joke.

"Well hello there, Reggie," a soft voice said.

A pale girl with even lighter hair knelt before him.

"If Loony likes the cat then you know he's weird," Regulus heard Ron whisper to Harry. Harry responded with a quick kidney jab to silence his friend.

"I personally think that he's more of a 'Leo'," Harry smiled at the strange girl.

"Yes, he's also a Leo," Luna nodded. She shifted to sit cross-legged in the middle of the corridor and held her hand out to the cat. Regulus nuzzled her hand with his head.

Regulus recalled a peculiar girl, Pandora, a few years above him in Hogwarts who was very similar to the one before him.

"I'm sorry, but we have to get to class now," Hermione said before bidding farewell. She scooped up her cat in her arms and soon forgot the exchange.

The following weeks were relatively calm for Regulus, but there was an underlying current of anxiety that had begun to build. He spent the majority of his time stalking Pettigrew and terrifying the rat any chance he got. But he couldn't help but worry about Hermione.

He learned that the girl was absolutely brilliant. She was obviously book smart, but Regulus could see that she was so much more than that. That was why he was completely baffled by just how stupid she was when it came to taking care of herself.

She was usually last to leave the common room at night, first to arrive at the library the next morning; she had shadows like Lupin's under her eyes and seemed constantly close to tears. Regulus knew her schedule by heart. He walked with her to all of her and knew that after Divination she went to an empty classroom three doors down to go back in time in order to make it to Muggle Studies. Her schedule was rigorous.

It wasn't until three weeks in that she finally broke. Curfew was approaching, and Hermione had yet to return to her dormitory. Regulus made his way down to the library. The curly headed brunette was slumped over a dusty textbook. Her sweater was wrinkled, and her hair frizzed around her. He padded his way over to her and jumped on top of the table and nuzzled her hair. She blinked away the sleep and moved forward to pet him. It was at that moment that they both realized that something was amiss.

"Oh my god," Hermione said, her face scrunching up as tears began to pool down her face. "I completely forgot that the Time-Turner would change when it happened." Her face was blotchy, and Regulus was not quite sure what to do. Sure, Regulus knew that half of the population bled monthly, but he had never actually witnessed the panic that came with it.

Regulus fled the library and ran to the Infirmary. It took a good five minutes to locate a feminine hygiene product. Why were there so many different kinds? When he returned to the library, Hermione was sniffling and packing her worn satchel.

She saw the wrapped pad that he carried with his teeth and her eyes began watering again.

"You're the best, Crookshanks," She wailed and picked him up to hold to her chest.

Regulus was really worried about his little witch. The more that Regulus thought about it, the more he realized that he hadn't seen her eat a full meal or sleep for eight hours since she came to Hogwarts. Maybe he should cut back on hunting Pettigrew and make sure that Hermione was taking care of herself? She was his only friend and a good one at that. He needed to look after his best friend.