Dear Readers,

First, it has been a LONG time since I've read the books and I'm only recently rewatching the movies, so if someone seems OOC, I'm sorry and will try to fix it. Most of this comes from the Harry Potter Wiki to help fill in the gaps.

So, originally there was just going to be one chapter for the prologue but then it got so big I've had to split the prologue into chapters and make it the first half of the story, basically recounting what happened if Alex was Draco's brother and they lived together, and then the second half is the actual story. As for the title, both phrases are from French and mean this, as translated by Google:

Mal Foi = Bad Faith
Bonne Foi = Good Faith

1981:

It was a cold, dark night, not a nice night to go out and do something, whether it be evil or good. Narcissa was in the nursery, warming her hands with the help of a small fire as the night wore on. Her son slept soundly in his crib, despite the howling wind and freezing night. It also helped that his mother had cast a charm on the blanket to keep it just the right temperature for Draco, he wouldn't be too cold or warm (who could get warm in this weather?). Lucius was out with the Dark Lord, trying to break the prophecy, and Narcissa could only hope for her husband's safety. She loved him, she really did, but she had her son's life in mind, how it would affect him if he grew up without his father.

It was at that moment that Narcissa stiffened, the alarm charm over Malfoy Manor wavering slightly as something entered the premises. The charm warned her of the intruder, having not done so otherwise if she had known the person, and so she moved to the window to get a look at whoever had entered. Much to her alarm, not one person had entered, but four, causing her to tighten her grip on her wand. She was a good witch, but she couldn't take them all on by herself, especially with Draco near. He was the more vulnerable of the two of them and she didn't want to risk his safety. Her only choice was to apparate, but before she could, a commotion began outside. She watched in amazement as bangs and flashes cut through the air, the four men being cut down before her eyes as other people entered the area, closing in on the area where the men had fallen. Draco began to sniffle and whine at the loud noise and Narcissa had to calm him back to sleep. The protection spell over the manor prevented it from being hurt by most weapons and spells, so she didn't have to worry about losing the home, because she was sure those were Muggles and they had been fighting each other with their own weapons, but she wished there was a silencing charm over the nursery. After checking the fallen men, the bigger group then began to fan out around the area and Narcissa worried that they would try to enter the manor, even though she knew they couldn't really see it. The manor had been enchanted to look like a big brick wall to muggles, so that they wouldn't try to go inside, but she still worried. And after many many minutes, eventually the large group moved off. Sighing in relief, she moved away, but then paused as she considered why the group had been looking around, even after killing the four men. Had the fleeing group lost something that belonged to the second in the illusion of the manor? If so, she wondered what it was. Checking on Draco one last time to make sure he was okay, she went downstairs and left the manor to investigate.

She gave a sound of disgust when she found that the second group had left the bodies behind, but ignored it in favor of searching the ground around the manor, which was also under the illusion. That's where she found the basket, baby and all. It had dirty blond hair and big brown eyes and couldn't have been too much older than Draco, certainly not by a year, and she was almost sure it was a boy. He giggled at the sight of her but his cheeks were flushed from the cold, he must have been freezing. But what was so important about a single baby that people were willing to kill for it? Of course, that's exactly what the Dark Lord and Lucius were doing at that moment, but this was a different case. This was a muggle baby, there was nothing about a muggle baby that was special unless he was the son of an important muggle, but why? Well, she couldn't just let the babe freeze, so Narcissa took the basket into her arms and began to move inside when another thing happened.

"H-hold it!" Her head shot up when she found a muggle pointing the small barrel of something at her and she realized with dread that she had accidentally stepped outside the illusion. With her hands full of the basket, she had no way to defend herself, leaving her at the mercy of the muggle, who seemed to have the same outfit as the downed men.

"I don't know how you suddenly came out of that wall, but I want you to give me that baby right now." hissed the man. Narcissa may have not minded killing, but she didn't like the death of a child to be on her head. She wanted to play the part of a frightened woman (which she certainly was in this situation) but from the way the man looked, she didn't think he would be nice to her if she did, so she stayed calm.

"Why do you want him?" she asked, "Why is he so important to you?"

"You have no idea how important he is. Now, hand him over." Narcissa couldn't let him take the child now, so she prepared to run if she could, when the door to Malfoy Manor banged open.

"Avada Kedavra!" A flash of green light flew past her and hit the man, killing him instantly, and she didn't need to look back to see who had saved her.

"Are you alright?" asked Lucius, sounding out of breath as he rushed to her side to make sure she was okay.

"I'm fine." she assured and they made their way inside the building. They would get rid of the bodies later, both of them seemed shaken up at the moment.

"What happened?" Narcissa shook her head, bringing the baby upstairs with her to the nursery, Lucius following.

"There were two groups of Muggles, they just appeared and fought each other and killed one of the groups. The second searched around after the first was dead and I was curious what they were looking for when they moved away and I found this." She showed him the baby, "I didn't realize I'd stepped out of the illusionment charm until he threatened me. Thank you for saving me, Lucius."

"And Draco?"

"He woke up once when the Muggles fought, but he's back to sleep." Upon arriving in the cozy room, Narcissa put the basket down and went over to check Draco again. He was still sleeping soundly, "How did the mission go?"

"Not well at all, I'm afraid." Lucius's voice, though he sounded calm, was burning with rage as he crouched to examine the new child, "There was an explosion and it turns out both Potter parents are dead, but their son… He somehow survived." This caused Narcissa to turn to face him in shock.

"Survived?! But the Killing Curse-!"

"I know, yet he survived somehow." Lucius spotted something tucked into the side of the basket and took it out, finding it the be a letter hastily slipped in, as it was slightly crumpled. He soundlessly stood and opened it, beginning to read. Narcissa knew better than to bother her husband when he was reading, so she picked up the unnamed child and held him in her arms, trying to get him warmer.

'Lady Rothman,

'The mission was a success. Alexander now in Scorpia's care. Sending him to you.'

"Alexander..." mused Lucius, "What an interesting name for a Muggle..." He spat the word with no mercy.

"Many muggles are named Alexander, you know that, they just tend to have their names shortened to Alex." Narcissa pointed out, "But Lucius-"

"No. We are not keeping a muggle baby. I know your stance on blood purity, why are you even suggesting it?"

"I may be a pure-blood, but I am a mother first." Narcissa looked down at Alex, "Only for a few years, Lucius. Then we may get rid of him any way you want." Lucius was quiet for a few moments, then sighed.

"Fine." he rubbed his forehead, "We get rid of him before he turns seven, though, just in case he turns out to be a mudblood. That would be worse than having a muggle in our family."

"Of course." She went over to her husband, "As it is, both of us will have to take care of him the same way we do to Draco."

"That doesn't mean we have to like it, though. We can take care of him, but that doesn't mean we have to love him." Lucius pointed out. It was also at that moment that Alex gave a small giggle and reached up, grabbing the wizard's long hair. Lucius winced at the pulling and gave Narcissa an annoyed look, even as she looked amused at the turn of events. She gently got Alex to let go before putting him with Draco, as there was no other crib for him and Draco's was so large. She knew it was a gamble, as neither of them knew how Alex or Draco would react to the other, but luckily, it was all fine. Alex even snuggled under the blanket with the sleeping Draco and fell asleep beside the other blond babe, causing both parents to smile. Lucius managed to pull his wife away from the cute scene and they moved out of the nursery, where they then debated on all the specifics they would have to do for Alex to 'become' their son. They had no idea how much of a change this would be, if they could have seen their futures before this.

1984:

As they grew up together, Alex and Draco grew close, despite how differently they were raised. While Draco was doted on and loved, Alex wasn't seen as much more than a housekeeper like Dobby, and yet the two boys still considered themselves 'brothers,' no matter how hard Lucius and Narcissa tried to make them see otherwise. Alex also proved to be a lot of trouble at times, even though he had no magic, and lovingly annoyed the Malfoys to no end. He also managed to bring Muggle things into the manor somehow, like a 'soccer ball,' or a 'record player' and Lucius and Narcissa seriously wondered how he managed to get hold of these things in the first place.

It was when the boys were four that the Malfoys decided to do something about Alex, but Draco didn't want to go anywhere without his brother, so Lucius and Narcissa tried to come up with ways for Draco to leave the boy alone. But like his brother, Draco was persistent.

"But can't I have candy too?" "You never let him play with me, I wanna play with him today!" "He promised to show me his circle-player-thing and I don't know that you know how to use it."

Draco may have been persistent, but much to their astonishment, Lucius and Narcissa also found themselves caring about the boy they had taken in, and knew they couldn't kill him themselves. So, they tried to take him away from Draco long enough to let him get killed by one of their Death Eater friends or let Fenrir curse him, but it was still proving to be a problem, even after they finally managed to get him alone. Alex kept slipping away back to his brother or somewhere else, even when they tried to lock all the doors and windows in the room.

"I swear that boy either knows secret passages in this place that we don't, or he's already showing magical ability." said Lucius after they lost Alex a fifth time.

"He could possibly be doing both." Narcissa suggested, "And yet-"

"No." Lucius protested, "We promised ourselves to never say it-"

"But we both know we feel for Alex." She pointed out, "We can't ignore this."

"Yes we can. As soon as Alex is with someone else we won't care about him anymore." And that was that. But, as Lucius had suspected, there were passages in the manor that neither he nor Narcissa knew about, and Alex knew how to use them well. He knew almost every nook and cranny of the house by this time and was putting it to good use, sneaking away from his parents. Alex thought of it as a fun game but he was curious about why his parents were showing him so much attention now. Did they change their minds on liking him? He hoped so. It was at that moment he came to the end of the dark hallway and opened the secret door into the living room, near his brother, and so he joined the other in playing with some Dancing Doxies, where the passage closed behind him.

"You got away again?" asked Draco, "How'd you do it?"

"I dunno, but it's fun!" Alex grabbed his toy hippogriff, which he had named Jack for a reason only known to him, and pretended that Jack was beating up the Doxies. It was another of the objects he had somehow managed to smuggle into the house, but he had gained such an attachment to it that the Malfoys couldn't force him to part with it, and so he kept it with him near-constantly when he was home. Alex never liked to take Jack on trips because he was afraid that Jack would get 'hurt' or something, and so the toy hippogriff was carefully handled, quite the opposite to right now.

"Caw caw, evil Dixies! Fear the great Jack the Hippiegriff!" Alex still had some trouble with his 'o's (with the exception of some words), so he substituted them with 'i's.

"What did they ever do to you?" Draco moved some of the Doxies away from the stuffed creature.

"They're Dixies!" Alex said, as if that explained everything. It was at that moment Narcissa and Lucius came into the room, having tired themselves out looking for Alex.

"There you are!" exclaimed Narcissa as she picked up Alex, who still held his toy, "How did you get all the way back here?"

"I'm special!" Alex smiled and his sweetness caused Narcissa to smile as well.

"Oh Alex..."

1987:

Alex laid on his bed in the opposite way, his stomach down and his head on the footboard end, his feet swinging in the air. His arms were crossed, propping his head up as he stared through his window. It was his seventh birthday, which he shared with Draco, but it wasn't really all that happy. Draco got to go out and celebrate while Alex had to stay home, the only company being Dobby. None of his family was nice to the house-elf except for him and that was mainly because Alex was always a little discarded, and so he ended up bonding a little with Dobby.

"Is Master Alex upset?" Speaking of the house-elf, he was in the room with the disappointed Alex.

"A little, yes." the boy agreed, "I mean, Draco is my brother and I love him, but he always gets everything. I either get things he shares with me, things I find, or nothing. It's just not fair sometimes!" Alex buried his face in his arms and said in a muffle, "Don't Mum and Dad love me?" Dobby's ears drooped, understanding a little of the pain Alex was feeling.

"Dobby thinks they do, Master Alex." said the house-elf. The boy raised his head to look at Dobby, his eyes a little red from beginning to cry.

"Thanks, Dobby." he sniffed.

"Is there nothing Master Alex can do to be cheered up?" Alex thought for a moment, then sat up.

"Actually," he began to smile, "I think there's something I can do! But you have to promise not to tell Mum and Dad, okay?"

"Dobby promises!" Dobby crossed his heart and smiled as Alex jumped up, grabbed his toy broomstick, and ran out into the hall for whatever mischief he had planned. It was still Dobby's job to protect Alex (as instructed by Lucius), so he followed the young Malfoy into the rest of the house. What ensued was marginal chaos, but luckily not enough to break or damage anything (with the exception of the weird vase Alex didn't like, but Dobby managed to fix that with his magic). And so Alex made his own fun with Dobby guarding him until his parents came home with Draco, and when they were alone, Alex told Draco about his antics.

"I wish I'd been there!" whined the lighter blond boy, "All I got was ice cream and a chance to see the Eiffel Tower!"

"Isn't that fun?" asked Alex.

"No. It's boring."

"I'd love to see the Eiffel Tower."

"It's just a big hunk of metal."

"Yeah, but it's still cool."

"Stays you." And so the conversation turned over to something else for the moment. But at the end of the night, when everyone was going to sleep, Alex summoned Dobby to his room.

"Yes, Master Alex?" The house-elf didn't expect the hug that suddenly appeared, but he accepted it anyway.

"Thanks for cheering me up, Dobby!" he said, "I love you, you're the bestest elf ever!"

"Dobby was happy to help, Master Alex." And Dobby truly was happy to have a friend amongst the family that abused him, it made things better.

1991:

Alex was glad to get out of the house, even though it was one of the few times he was allowed to do so. It was the beginning of August and the Malfoys were going out to get supplies for when Draco went to Hogwarts (after some lengthy arguing about whether he should go to there or Durmstrang, Narcissa won out). Alex, as predicted, never showed any magical ability, let alone got a letter, so he wasn't going to any school except a Muggle one, and the only reason why he was out today was because Draco was nervous and wanted his brother to be with him. And so, much to his parents' slight irritation, they agreed. Because there was so much Draco needed for Hogwarts, the family decided to split up to gather everything. Lucius would get the books, Narcissa would search for a wand (but she couldn't choose for him and the boys didn't quite understand why), and Draco and Alex would go to Madam Malkin's together. Their parents hoped they wouldn't cause trouble, but they couldn't in a clothing store, even they knew that, so Alex just had to sit around while Draco got fitted. He only cheered up when another boy entered the shop, black-haired, short, scrawny, and pale. Alex also noticed the scar above his eye (which seemed familiar), but didn't comment on it. In fact, he stayed quiet the whole time.

"Hogwarts, dear?" asked Madam Malkin when the boy seemed like he wanted to say something, "Got the lot here — another young man being fitted up just now, in fact." Alex observed as the boy got on a stool next to Draco and began to be fitted. Draco, of course, was the more talkative of the two brothers, so he began to speak to the boy.

"Hello," he said, "Hogwarts, too?"

"Yes."

"My father's next door buying my books and my mother's up the street looking at wands." said Draco and Alex rolled his eyes. Of course the lighter blond would try to make conversation to impress another kid. That was so like Draco, "Then I'm going to drag them off to look at racing brooms. I don't see why first years can't have their own." Alex snorted.

"I think I know why..." Draco gave him a glare.

"Shut up, I'm trying to make friends!" Alex stuck out his tongue and Draco went on, "Ignore my brother, he can be a pest sometimes."

"I know you are but what am I?" Alex mocked.

"Anyway, have you got your own broom?" The boy, who had been watching the brothers argue like he was witnessing a tennis match, started before answering.

"No."

"Play Quidditch at all?"

"No." And now Alex was becoming suspicious because he was sure there had been a small amount of confusion to the other's face before he answered. Who in the Wizarding World didn't know what Quidditch was?

"I do — Father says it's a crime if I'm not picked to play for my house, and I must say, I agree. Know what house you'll be in yet?"

"No." Alex was now almost certain that the kid had been raised by Muggles.

"Well, no one really knows until they get there, do they, but I know I'll be in Slytherin, all our family have been — imagine being in Hufflepuff, I think I'd leave, wouldn't you?"

"I think Hufflepuff is nice." Alex commented.

"You'd probably be one too." Draco shot back. It was widely speculated by the two boys from their knowledge of the Four Houses that Draco, of course, would be in Slytherin, but it was a debate on whether Alex would have joined him or the friendly Hufflepuffs, since he wasn't smart enough to be a Ravenclaw or brave enough to be a Gryffindor.

"Mmm." said the boy, as if he didn't know of anything else to say. It was at that moment that the brothers caught sight of a large man in the window, causing them a small amount of surprise, as they had never seen anyone taller or bigger than their father, and yet there the man was!

"I say, look at that man!" Draco nodded to the man in the window.

"Oh, that's Hagrid." explained the boy, who seemed to be pleased with himself that he knew something the Malfoys didn't, "He works at Hogwarts." Alex gazed at the strange man, realizing the name was familiar.

"Oh, I've heard of him, he's sort of a servant, isn't he?" At that remark, Alex glared at his brother, tempted to kick over the stool he stood on. Before Alex could reprimand Draco (as he was the kinder of the two), the boy beat him to it.

"He's the gamekeeper." said the boy, frowning.

"Yes, exactly. I heard he's a sort of savage — lives in a hut on the school grounds and every now and then he gets drunk, tries to do magic, and ends up setting fire to his bed."

"Draco..." Alex said in a warning tone, not wanting to get into a fight here or for his brother to keep insulting Hagrid. Alex, though growing up in a bigoted household, tended to think well of most everyone. His brother, however, was usually the opposite.

"I think he's brilliant." the boy said coldly, now glaring at Draco as well.

"Do you?" Draco sneered and Alex knew he was going in for the kill, "Why is he with you? Where are your parents?"

"They're dead." the boy said shortly and that caused Draco to look considerably shocked and ashamed. The brothers had suspected that Alex was adopted, being different enough from both Draco and their parents on appearance and attitude, and so the mention of not having real parents reminded Alex of why he was there himself.

"I think that's enough." he snapped to Draco as he stood, then turned to the boy, "I'm sorry for my brother, I hope you'll forgive us."

"...I'm sorry." was all Draco could manage, and he meant it. The boy, seeing how apologetic the brothers really were, softened slightly and nodded. He may not have completely forgiven them, but he was okay with them realizing they had stepped too far (though it was really all Draco's fault in that instance).

"That's you done, my dear." Madam Malkin spoke to the unknown boy and, before the Malfoys could ask for his name, he ran out of the shop and to the safety of the giant of a man. They got the feeling that wouldn't be the last time they saw him, though, certainly not for Draco.

Sometimes Draco was embarrassed with his family, especially with how his mother sent him letters and sweets every single day. But it was thanks to this that Draco was notified that something was wrong when he didn't get these special things for a few days, and during that time, he grew worried over the state of his family. Had something happened to them? Were his parents or his brother in danger? It wasn't until a fellow Slytherin showed him the newest edition of the Daily Prophet that Draco was given his answer: There had been some sort of explosion that had destroyed half the manor, no one was hurt, and it had happened a few days ago. There was a chance that his family couldn't contact him, but he hoped they would send a letter soon to make sure he knew they were okay. As it was, he asked both his Head of House (Snape) and the Headmaster (Dumbledore) if he could go home early for the holidays to deal with this, since it was already so close to the holidays. Both agreed, but only if Draco would make up for it when he returned, and he promised, glad that he was given a chance to check on his family. Just before he left for home, an owl came with a letter from his father, who assured that things were okay and that the manor was being rebuilt (most, if not all of the damage had been restricted to the roof and the boys' rooms), but also stressing that he had to come home for 'important matters,' which Draco translated to things that he couldn't discuss in public. It was a good thing he was coming home early, then, but there was still one thing on his mind that was bothering him: What had happened to cause the explosion? He hoped he would learn the answer soon, so he made his way back home on the train (but not before sending a letter to his parents to pick him up) and met his father at the station.

"Father-"

"Everything is fine, Draco, but I'm glad you've arrived. Come, we've got much to discuss." Draco took his father's hand and, in a few queasy seconds, they had apparated back to the manor. Draco never liked apparating, but he knew it was needed in this instance. He felt even worse when he took in the state of the ancient building, half of its top blown off.

"Were we attacked?" the boy asked as they began to head inside.

"No."

"Does it have something to do with Alex?" With all the trouble his brother caused, even Draco found it hard to believe that Alex would have done something like this. And yet Lucius paused and Draco knew it was the truth, "What did he do this time?"

"Draco," Lucius began slowly, "This technically isn't your brother's fault."

"What do you mean?"

"Have you ever heard of an 'Obscurial?'"

"N-no, Father. Is that something we're supposed to learn in school?"

"Not until History of Magic, and it's not something most know about." Lucius led the boy into the living room, where Draco found his mother with Alex, who looked so very different from when Draco had left to go to school. His brother was pale and unmoving, curled up into a ball on the couch and staring at nothing, his grip on himself tight, and Narcissa was trying to coax Alex out of this position. Draco looked at his father, almost asking for permission to go over to Alex, and Lucius nodded.

"Alex?" The other boy didn't move as Draco approached, even with the questioning, he was as silent and still as a statue. Even when Draco took a seat beside the other, Alex didn't move. It was only when Draco put a hand on his shoulder that Alex turned his head to look at his brother, and Draco found that his eyes were full of tears. Even if their father said it wasn't 'technically' Alex's fault, it was obvious the other was blaming himself for it. And so Draco hugged him, even if Alex didn't hug him back for a long minute or two. It was also at that point that Alex began to cry; not vocally, but Draco could feel the tears on his shirt and Alex was shaking slightly, indicating what he held back. After a very long time, what seemed like hours and they had pulled away from the hug, Alex finally calmed down enough to speak.

"I'm sorry." he sniffed, his voice raw despite making no sound, "I didn't mean to."

"We know." Narcissa assured, giving him a kiss to the head, "We're just glad you're okay now."

"I love you, Mum and Father and Draco, I'm so sorry-"

"Shh..." Narcissa moved Alex over to her side of the couch, hugging him and whispering soothing words to him, giving him Jack to cuddle, allowing Draco to leave the room with his father to ask more questions.

"Father-"

"Draco, I want you to listen to me for the moment." Lucius spoke, crouching to his son's level so that he would understand, "An Obscurial, what I mentioned before, is a person infected with a parasite called an Obscurus. They form in magical children who repress their magical powers by many different means, destroy whatever or whomever is the cause of the Obscurial's distress, and one hasn't been seen in many many years, but I believe your mother and I have accidentally made your brother into one."

"Why?" Draco found this hard to understand. How could Alex be magical? And his parents hadn't done anything to make Alex this way, had they?

"I believe both of you have figured this out by now, but Alex was adopted into the family. He is a Muggle we took in because of your mother, despite how we felt about Muggles, and so we never thought he would have magical ability. He never showed any, so he himself never thought he was magical, and I believe that was what made him into an Obscurial. We realized this when he caused part of the house to be destroyed."

"But why? Alex isn't a bad person, and you didn't do anything to make him mad, did you?"

"No, Draco, we didn't. I was having a meeting with some colleagues and Alex was apparently listening in, for when we got into a confrontation over something, Alex got involved and destroyed that part of the house while trying to protect me. No one was hurt, but you can't talk about this, Draco." Lucius gave his son a stern look, "As I've said, Obscurials haven't been seen in many years, and if this gets out, I don't know what will happen to your brother."

"I promise not to say a word." And Draco meant it, "But Father, is there a way to cure Alex?"

"...I don't know." Lucius stood, shaking his head, "Newt Scamander was the leading authority on magical creatures a long time ago, including the Obscurus, but I don't think even he knew how to get rid of one and save the life of the child at the same time. Now come, we have a lot of things to do before you go back to school." The boy took his father's hand and knew that, no matter what, he would not only have to be nicer to Alex but do his best to protect his brother. He couldn't let Alex's Obscurus get the best of him, and so Draco would protect him from others and himself the best he could. He didn't realize how big of a job this was quite yet.