Decima hated turning in her essay in Transfiguration knowing she would fail it, but it was better to show that she had made the effort than to not turn in anything at all. Professor McGonagall glanced down at the parchment with pursed lips and said, "See me after class, Miss Zimmerman."

She could feel the eyes on her as she blushed and nodded, not daring to meet even the eyes of Regulus or Gwen. Everyone knew she was horrible at Transfiguration, but it didn't make her feel any better to have it pointed out in front of everyone in Slytherin, especially after Sirius Black had just asked Philomela to Hogsmeade for that weekend. Decima didn't know why, but she wanted to scream, and the horrible scenes playing through her mind of how McGonagall would punish her for her abysmal essay didn't help her mood.

As soon as the bell for class rang, she told Regulus not to wait up for her, not wanting him to see her cry, which she knew she would be doing when she finished her, and she also knew it was completely irrational. There was no point in being ashamed of the best she could do, but she was still ashamed. Heart pounding in her chest, she waited for the other students to empty the room before moving toward Professor McGonagall's desk. Just as she was about to ask why Professor McGonagall wanted to see her, the door swung open again and in sauntered Sirius Black, smug, confident, and suave as he made his way to the desks in the front row and sat on top of one.

"Present and accounted for, Professor," he said with a smile.

"I noticed, Black," she said. "Miss Zimmerman, I have decided you need a tutor, and after careful deliberation, I asked Mr. Black if he would take the job."

No. No. This couldn't be happening. This was all her fault for not hiding her essay when Sirius asked about it. It was all her fault for letting him know she was bad at Transfiguration. It was his fault for taking such extreme measures to be alone with her. It just wasn't fair, damn it!

"Who else were you considering, Professor?"

Professor McGonagall frowned and said, "Well, not that it matters, I thought about James Potter, but their skills are very similarly matched and I think Mr. Black would be a better teacher for you."

She wanted to fight back. She wanted to say no. She wanted to beg Professor McGonagall to put her with anyone else, or no one at all, to swear she'd do better. But that wasn't exactly something she could swear, and she knew resistance was futile. Regulus would be furious.

"Well," said Sirius, "should we start tonight?"

That smirk, that arrogant smirk. She wanted so badly to smack it off his face, but she just smiled politely and nodded, saying, "Yes, Sirius, I think that would be fine."

Regulus wasn't happy, but the order had come from Professor McGonagall, and she was one of those women you just didn't argue with if you valued your free time. Somehow, Decima managed to survive the week, and Sirius behaved himself quite well. Sure, he stared at her, but he didn't make any unnecessary physical contact and he didn't say anything suggestive. It was probably a ploy to get her guard down, but it wasn't going to work.

That weekend, Decima pulled on a long-sleeved green shirt and jeans, trying to look reasonably modest, but knowing Sirius would stare at her anyway. She mentally chastised herself. She wasn't dressing for Sirius anyway; she was going with Regulus and ought to be dressing for him. Still, she put on her makeup and put her hair up in a ponytail, thinking the whole time how to not look too good, since Sirius was going to be bad enough just with her being there. They walked out to meet their fellow students, heading to Hogsmeade in a large, boisterous group.

They reconnected with Sirius and Philomela at the entrance to the Three Broomsticks, and Decima realized that the other Marauders were joining them as well. Not only was this going to be awkward, but Decima didn't know how to act. The Marauders saw her without all the pretenses that Slytherin required, and she didn't know how to live in both worlds at once. Mind running through a million worst-case scenarios, she slid into the booth after Regulus, noticing him tense as Sirius slid in after her.

"So, Decima," said James, "we've missed you at our table. Your laugh was a wonderful addition to our jokes."

She laughed in spite of herself and said, "Well, Sirius is my tutor again, so maybe you'll get lucky and see more of me."

"James doesn't think he's gotten lucky until he's gotten into Lily's pants," said Peter solemnly. Sirius, Remus, and Decima roared with laughter while the Slytherins sat uncomfortably by and James blushed furiously.

"Hey, it will happen!"

"Sure it will," Decima said dryly, "and I'll get into Sirius's."

She realized how that sounded almost as soon as it left her mouth, but it was too late to take it back. Regulus was already freaking out and Sirius was staring at her with an odd sort of look on his face, somewhere between hurt and desire.

James waited for Regulus to run out of air from telling her off and said, "So, like I said, pretty good chance, then."

As Regulus stared off again, James just winked at her and drank his butterbeer as she tried desperately to calm her raging boyfriend.

"Sweetheart, it was sarcasm. It was sort of like saying 'When Christa gets with the Giant Squid.' I didn't mean it, please stop overreacting, people are staring."

He eventually calmed down, but he kept a possessive arm around her waist the whole afternoon, glaring daggers at his brother every minute or so. Sirius didn't seem to notice or mind, and his leg was pressed against Decima's in a way that let her know it had nothing to do with them being crammed tightly around the table. After the week had gone so well, Decima just wanted to crawl in a hole and die, and all because of something she said. And she thought Sirius was going to be the problem!

Sirius actually was a good teacher, she found out, and he did seem intent on her learning as much as possible. Her performance in Transfiguration was improving so drastically so quickly, Professor McGonagall started to ask her if Sirius was doing her homework for her, when she thought about it and said that Sirius never even did his own homework, so never mind.

The days grew shorter and colder and Decima found herself spending more and more time with Sirius in the library, studying, practicing, talking, and just being around him. She told herself rationally that she wasn't falling for him, he was just good company. She held true to her promise to James and frequented the Gryffindor table for a meal every other day, at the least. Her behavior had actually gotten her talked to by several Slytherins, who were worried she was betraying them. The excuse of her Transfiguration grade was being stretched so thin that few people were buying it anymore, including Regulus. Still, she couldn't make herself stop.

"So," he said one day in early December, as she sat with them at breakfast while Professor McGonagall went around collecting names of those staying over the holidays, "are you still going home with us over the holidays?"

Decima nodded and buttered another piece of toast.

"Yeah, my parents wouldn't let me do otherwise at this point."

"Wait, you're staying at the Black's place?" said James incredulously. "Sirius never lets us come over."

"My parents wouldn't let you come even if I asked, Prongs," replied Sirius. "She's not my guest, she's my brother's, and you're forgetting that her family is in a lot better favor in our community than yours."

Decima shifted as James nodded. There was so much in that status that ranking that purebloods had for their families, and it made her own home life hell sometimes. When her parents found out she was dating a Black they were over the moon, though they were a little disappointed it wasn't the eldest, until they learned that Sirius was the black sheep and not likely to inherit, anyway. Sometimes all the society and expectations was drowning, and there was no escaping it in Slytherin. Severus Snape was refreshing, since his best friend had been Lily Evans, a Muggle-born witch, for five years, and Decima was close to certain that his father had been a Muggle, or Muggle-born at least, since there were never any Snapes at the pureblood parties she and the Black boys had been attending since birth.

"Anyway," said Sirius, derailing her train of thought, "I just wanted to tell you to be careful."

"What?"

"Be careful, Decima, when you come to my house. I don't think they'll hurt you but…"

"What makes you think they might hurt me?"

Sirius sighed, "I don't know, maybe because the do it to me every time I go home. You'll see. I doubt they'll refrain just because we've got a guest. With your family's standing, they'll expect you to just take whatever they dish out, at you or me, and to keep your mouth shut about it."

Somehow, that wasn't surprising. Her own family had beaten her sometimes growing up, but Sirius sounded actually scared for her, which was strange. Her parents might not have been the most humane disciplinarians, but they would never permanently harm their only child and heir, especially the daughter. Scars didn't look good on a young woman who was supposed to be married off to a nice pureblood young man. Nobody wanted a disfigured wife.

"Well," Decima said, "I think I can handle myself. I was raised pureblood too, remember?"

He nodded and said, "Just promise me you'll be careful. Try not to step on any toes."

"Again," she snorted, "raised pureblood. I think I know how to avoid a conflict."

"Really?" said Remus doubtfully. "You seem to have them happening all around you this year."

"Well that's not my fault," she said, looking pointedly at Sirius.

"Oh, I don't know, love," that suave boy said. "I seem to remember you stepping into that mess at Hogsmeade all on your own."

Oh he just had to go there. With a sigh, she took a bite of her toast, bid them goodbye, and returned to her dormitory to pick up her books. It was only a short while until the holidays. She just had to make it a little while and she could just focus on being with Regulus and impressing his parents. It shouldn't be that hard, she spoke with them nearly every year at the balls and parties the pureblood society put on, even if only briefly. She knew how to act, what to say, whom to flatter and whom to defer to. She just had never had to play that game on a daily basis before, in everyday life, with a rebellious teenage boy in the house who not only didn't get along with the rest of the people in the house, but wanted to shag her senseless if she gave him the opportunity.

Maybe this would be harder than she thought…

Somehow, Decima managed to make it through the days without having to eat words and without sticking her foot in her mouth with Regulus again, which was good, because she didn't want to think about being at his house while they weren't on great terms. Sirius had behaved like a proper gentleman, and she had taken to eating almost exactly half of her meals at the Gryffindor table because the company was just so much more enjoyable. Screw the rumors. It was nice to eat a meal without having to worry about what she did and said every once in a while. Even if she said something stupid, the Marauders just laughed it off. That didn't happen with her friends.

She and Regulus sat in a compartment to themselves on the way back, snogging a lot of the way, of course, but also talking about the term and how they felt about the rest of the year. She rested her head against his body, feeling his warmth and breathing him in eagerly. She really did care about Regulus, and she certainly liked him, but his behavior lately had been odd, scattered, and not like his usual self at all. She supposed the same could be said about her, but there was an explanation for her odd behavior, and it was all out in the open. Decima couldn't seem to understand why Regulus was suddenly all jumpy and anxious, why he was short with her when she had done nothing wrong and why he had even been neglecting his prefect duties more often than not, and she found herself making excuses to Longbottom.

When they arrived at King's Cross, Regulus got her things off the train for her and then got his own. Sirius said goodbye to the other Marauders as soon as they were on the other side of the barrier and joined them, the trio walking up to Mr. and Mrs. Black, who were standing to the side, waiting impatiently for the three teenagers.

"Decima Zimmerman," said Mrs. Black, her voice shrill and cold, though Decima knew it wasn't personal. She just sounded like that with everyone.

"It's wonderful to see you again, Mrs. Black," Decima said graciously. "I'm much honored that you have welcomed me to your home for the holidays."

Mrs. Black nodded as though to say that she should be grateful indeed and led the way to the Muggle car Decima knew she must hate. Mr. Black, Mr. Orion Black, gave her an unreadable gaze, kissed her hand as was customary, and grabbed her things, as was also customary, making sure that she needn't break a sweat.

The ride to Grimmauld Place was silent and Decima found herself somehow awkwardly sandwiched between Sirius and Regulus, neither of whom, surprisingly, wanted to touch her at all with their parents in the car, even if they could make it look like it was accidental. She had never seen Sirius so dejected before.

The house was, well, interesting. It was dark, gloomy, and rather like many pureblood houses, though surprisingly without the grandeur she had expected of their station. The heads of dead house-elves in their hall was certainly an unpleasant shock, but she kept her face as level as possible as Regulus led her to the kitchen for some supper.

As soon as the kitchen door closed, Decima could hear the sound of a hand making swift contact with a face and she knew Mrs. Black had just slapped her eldest son. She shifted uncomfortably, eyes glued to the door, although Regulus hadn't seemed to notice the voices now raising from the hallway, yelling at him for his behavior, the letters they had received about the number and nature of his detentions, and about how he was such a disgrace to the family. Perhaps Regulus was just pretending not to hear. There was no way he really couldn't hear this.

She stared down at the plate the house-elf had sat before her suddenly not hungry as she heard Sirius grunting in pain outside the door. She hadn't expected them to assault him the minute he walked through the door. Decima did poke through her food, but when the kitchen door swung back open and Sirius came in with a bloody lip and a handprint burning on the side of his face, she dropped her fork and gave him a pained look. He met her eyes with a stony face before dropping his eyes to the floor and sitting down to eat.

The situation with Sirius and his parents didn't seem to diffuse with time. In fact, the longer he was home the more ways his mother and father came up with to torture him. One morning, she saw him copying from a book of pureblood societal doctrine with a quill, parchment, and no inkwell while his mother looked on, sipping her tea. Decima sat down to breakfast and tried to ignore the oddity of the situation until she saw Sirius's face screwed up in pain and concentration as his hand moved across the page. She could see blood soaking through his Muggle t-shirt. Mrs. Black was making her son write with a blood quill. She was actually torturing her own son. Suddenly, Decima had no appetite.

There was no time alone with Sirius, which she should have been grateful for, but instead, she found it irritating. She wasn't sure why, but Decima would sit down with Sirius in the parlor and one of this parents must have sensed it and would walk in and sit down only seconds later. They gave her plenty of time alone with Regulus, however, and Orion had actually offered for them to share a room, but Decima declined, knowing that even if it was offered, it wouldn't be proper.

Sirius was far from his usual self; in fact he was something like a kicked dog. He hardly talked, he never laughed, and he didn't stare at her. He hardly looked up from the floor. In fact, one night at dinner, something she said caused him to look up and wink at her, and that action alone was enough to make his parents completely lose their tempers with him. Decima looked on in horror as Mrs. Black began to use the Cruciatus Curse on her own son. Sirius cried out in pain, falling out of his chair and writhing on the floor. Regulus could see the tears forming in Decima's eyes as she watched Sirius twisting in pain and he took her hand, leading her out of the room.

"Go to bed, CiCi," he whispered in her ear outside of the room they had set aside for her. "Sirius is going to have a long night."

She accepted his goodnight kiss, but she didn't kiss him back. Her mind was in a sort of shock from what she had just witnessed. Maybe Sirius was right. Maybe she shouldn't have come.