This is an AU in which A did not commit suicide while at Wammy's, but rather he ended up becoming the official successor to L. This changes a number of things in the canon, one being that B is less preoccupied with L and instead interested in his old roommate, A. Because of this, the LABB murder case does not happen, and instead B is involved in another case that gets A's attention, which is addressed in the story. Everything after that pretty much follows the canon though. The A in this story is pretty much the same one from my other fic, Earning First Place, but this is not a sequel.

Awkward and unhealthy relationships away!

Blood Types

It was well past midnight, and A was still sitting in the middle of his livingroom floor, surrounded by files. There was a highlighter dangling from his lips and a red pen in his hand. Mixed in around his files were a multitude of coloured pens, pencils and markers. This was his method. A knew there were computer programs that he could use to find patterns and connections, but to A, nothing was better than seeing something on paper. Things became more real, more tangible on paper rather than a computer screen. A didn't even care for typing, preferring to hand write notes and illustrate solutions by hand. L had actually chided him a bit when A first started working, for his apparent technophobia, but when A delivered results, quickly and accurately, finding connections and solutions most wouldn't be able to notice even with the help of a computer, the detective had backed off and let his protégé do his own thing.

A did have a computer, a few actually, to print out files and to communicate. Currently though, all pieces of technology were stored in a large safe in the hall closet. A's peculiar living arrangements meant he had to be careful about leaving anything that could connect someone to the outside world out in and in easy reach. Living with his childhood rival turned violent murderer made a number of things difficult. When B had been arrested, after killing two homeless men on the streets of New York and doing very creative things with the intestines, A was faced with a number of choices.

B was a dangerous criminal, and it was reasonable to simply let the American justice system hand him; but after B was arrested, convicted and sentenced first to a prison then a high security mental institution, it became clear that the man had no business being around the normal population. Four serious assaults and seventeen escapes later A had stepped in.

A had been involved in the initial case, as L's official successor he was often handed cases that weren't quite to L's standards, and with only two victims, despite the brutality and mocking messages to authorities, L wasn't interested. Besides, A was already in New York, wrapping up a kidnapping case. A had realized when he first saw pictures from the first crime scene that B was behind this. He hadn't seen B since he ran off from Wammy's nearly five years ago. But when A saw the way the first victim's intestines had been carefully draped and wrapped around his neck, like some high fashion scarf, A immediately remembered watching B do the same thing to a squirrel when they were children.

B knew he was in New York, and this was B's way of saying, 'hey old friend, I am in town, we should hang out.' The second murder scene was even more of a calling card, it was very clearly staged, and as with the last one, the intestines were carefully placed around the body forming an elaborate letter 'A' in the same exact type face than he and L used when communicating.

Catching him had been too easy, and after the escapes and assaults, and overall bizarre and disturbing behaviour, the state of New York was more than happy to hand B off to individuals who claimed they could better restrain the wild creature.

So A set up base in New York. He liked the city, he supposed, he liked London better, but there was no way the UK was going to allow A to extradite a murder overseas with the promise of 'I'll look after him, I promise!' A faced a similar problem in other US states. Finally it was decided that New York was the best place for A to both set up shop and keep a pet murderer. So with the help of Wammy's and L, A purchased a large penthouse apartment, as well as the entire building below it, and installed an elaborate state of the art security system. At first B was housed in specially built cell in the buildings basement, but A was weak, and he knew he was weak.

Despite knowing everything B had done, not as though A was surprised in the least, A was drawn to his old roommate. Suddenly he was twelve years old yearning for B's attention and affection. When B had disappeared from Wammy's all those years ago, A was devastated, but quickly buried himself in school work, secretly hoping one day to use his detective skills and the power of L to track down his long lost roommate. And in a way, that was exactly what happened, only now B had a body count.

After B was incarcerated in the building A found himself visiting for hours at a time. Most of the time they didn't even talk, A worked on some case, pouring over files, while B either watched from his side of the security glass, or ignore him completely. After nine months of this A said fuck it, had his own penthouse carefully modified to be its own prison, and moved B up with him.

That had been over six months ago. B had been a surprisingly well behaved murderous house guest. Much like a cat, A would go days without seeing the man, before he would suddenly emerge demanding food or attention or both.

"'Lexi," a voice called from the backroom of the apartment and drew A's attention from his mess of papers. A grimaced at the shortened form of his real name, but decided to ignore the voice. He traded out the pen in his hand for a large marker and drew a sloppy box around an interesting bit of information in the case file he was reading.

" 'Lexi," the voice called again, and A dropped his head and let out a loud sigh.

"What?" A yelled back, his highlighter dropping from his month. He was met with silence. He shook his head and went back to reading.

Movement out of the corner of his eye got his attention. B was suddenly in the doorway dividing the living room from the hallway. B moved fast and quietly. Again, the man was the human incarnation of a cat.

A looked up to study his roommate turned prisoner. The wild child of B had grown up just as A had expected. His dark, wild hair was still a matted mess on his head. He had grown though, he was tall, at least 6', and his body was lean and sleek, anytime he moved A would catch glimpses of muscles flexing under B's clothes. He was much, much stronger than he looked. If it weren't for the security cuff around his ankle, capable of both shocking and giving B a large dose of tranquilisers, A would be seriously concerned about their size difference. A himself was short, barely 5'7'', and where B was deceptively skinny, A was just skinny. L had advised he pick up some form of martial art, especially after A took B into his care, but A had dawdled. He rarely did field work so he didn't feel the need. He did know how to shoot, though. It was something he had picked up shortly after coming to America, and anytime he was out of the apartment he had a gun in a holster on his ankle. But for obvious reasons, there were no guns in the penthouse.

B moved again and crouched at the edge of A's piles of papers. B was holding a book at his side; it was closed with his finger marking his place. B stared intensely at A.

"What is it, Beyond?" A questioned. B's face twisted into a scowl. A enjoyed the reaction he got. B didn't like his name, and preferred the simple letter, but if B was going to annoy A with his name, A would return the favour.

"What is your blood type, 'Lexi?" B replied in a hiss.

"I asked you not to call me that. And I don't know," A narrowed his eyes suspiciously as he studied B's face. "Why do you want to know my blood type?"

B grinned. It was wide, unnatural, and frankly terrifying, still A was used to it, and didn't respond.

"Nothing nefarious, I assure you," B said, sounding as innocent as a convicted murderer and psychopath could. B held up the book. The title was in Japanese. A studied it for a moment; Japanese wasn't a language he was very fluent in, he was much better with Romance or Germanic languages.

"Unlocking the Personalities of Blood Types?" A gave B a puzzled look.

B nodded. "So you don't have any idea what your blood type is?"

"No, blood types and personality isn't really popular in Western culture. Besides, you know all that is pseudo-science, right?"

"It is still very interesting," B said, "you can gleam a lot about a culture from the types of mythologies and mysticisms they create and perpetuate."

"Of course you would be interested in blood types rather than something like astrology," A said, rolling his eyes.

"Blood is so much more personal than vague star alignments. If I had to bet, I would put more faith in blood types over astrological coincidences," B shrugged and flipped the book open. "I wonder if I could guess your blood type based on personality."

A let out a short laugh. "There is absolutely no evidence that a person's blood type has anything to do with personality characteristics."

"Just a little experiment. I am sure Wammy's has both our blood types on file, let's see how our personalities match up." B was running his finger across the page as he spoke, trying to find a particular section.

"I have work to do," A said, but he was already setting his pen down, already being drawn into B's game. This sort of thing happened way more than A was willing to admit.

B suddenly leaned forward, so his lips were brushing against A's ear. "I could always cut you open and taste your blood. I am sure I could taste a blood type." B's voice was a low, dark hiss that sent chills down A's spin, and blood rushing in all the wrong directions. A couldn't help but imagine such a situation, and A quickly felt his checks go red. He was so very weak when it came to B.

It took A a second to recover. This sort of off handed threat of violence was common from B, but still took him off guard. Finally, he managed to respond.

"There's no physical way to taste blood types," A's voice was weaker than he would have liked. B backed off though, and returned to skimming through his book.

"Would you say you are a perfectionist?" B asked, eyes glued to his book.

"Probably. Most people would say they were, that's how these things work, appeal to vague, generalized characteristics that could apply to anyone," A replied. B just smirked.

"I'll put you down as serious and sensible, as well. Come on, this is a good experiment! You have no knowledge of your blood type so you won't be swayed by preconceptions." B seemed to genuinely be enjoying this. A sighed. He figured he could play along with B's latest game. A was too distracted to work anyway. He kept imagining B pinning him down, slitting his throat and lapping at the wound like a wild dog. A wondered if 'sick and twisted masochist' was a personality trait that could be associated with blood types.

B kept glancing between A and his book. It reminded A of a bug collector trying to identify a new specimen.

"How about socially, would you consider yourself a social butterfly?" B asked, and A couldn't restrain a loud laugh.

"Yes, total social butterfly," A said his voice loaded with sarcasm. The work of being next in line for L's title didn't leave A with a lot of time for 'socialization', not as though A would ever voluntarily choose to socialize. His day to day interactions were limited to his security team that helped him monitor B and keep them both safe, a small number of personal assistants that only appeared when he was really busy, and of course, B. Actually, more than 70% of A's human interaction was limited to B. Not exactly the healthiest social circle, but it was what A had.

"You always were a loner," B said after a moment. "So no to the social butterfly."

"It works for me," A replied with a shrug.

"Hm, how's your self-confidence?" B asked, giving A a knowing look.

A hesitated. Every sensible cell in his body, and despite was B said, there weren't too many of those, screamed to show as little weakness as possible around B. B was a predator looking for the weak prey to take down. A's self-confidence, or rather lack thereof, was not something he really wanted to discuss with B.

"It… It could use some work," A eventually answered.

B's lips curled into a sardonic smirk. "Tsk, tsk. You're L's successor that alone should give you all the confidence you could ever need."

A glared. "No one is perfect."

"Right you are, everyone has weaknesses and blind spots," B agreed. He stared at A a moment longer before glancing back at his book.

"How well can you multitask?"

A glanced around at his pile of work. There were at least seven different cases mixed together. He had no problem jumping from case to case, in fact, it helped him to see things he would have missed otherwise. He looked back to B.

"Pretty good," he answered.

"Never good multitasking myself," B commented, "When I first got to New York, I was so focused on getting my little events right that I forgot to eat for a week."

A shook his head. "That's not healthy," A replied, speaking to both B's diet and the fact that B just referred to brutal, violent murder as 'little events'.

"How impulsive are you? Would you say you 'go with your gut'?" B said, moving on. He was obviously quoting the last part directly from the book.

"Not very impulsive… I enjoy planning my actions, probably a little too much. I would say that trusting your gut is probably not the best course of action in most cases." A answered with a shrug.

B gave him a strange look. "You went with your gut when you caught me," he said. And it was true. A's whole approach to B's case had been unusual. It was all intuition, what he felt that B might do next, how he thought that B would act. It had actually been very hard to convince the detectives he was working with to follow his seemingly wild leaps in logic.

"I would argue that was because you made it too easy," A challenged. They had never had a direct conversation about the case before. At the beginning A had tried, but B didn't want to talk. It had always bothered A, though, how quickly B was tracked down. He knew B was smarter than that.

"Maybe I just couldn't wait to be your roommate again," B said with a dark laugh. And somehow, A seriously believed that was his goal in murdering two people and taunting the police for months.

"There were easier, less violent ways you could have made that happen, you know," A said.

"But not more interesting," B replied. A started to respond, but B cut him off, "Moving on!" B announced loudly and just like that the subject was changed. A knew from experience that there was no way of steering conversation when it came to B.

"Fine, what's next?" A asked.

"Of these careers, which would be the most interesting… if, you know, you actually had a choice in careers growing up." A rolled his eyes at B's jab at Wammy's. The man was rather resentful of Wammy and L's methods when it came to the children raised to replace L. B rattled off a short list of job titles, "Writer, military leader, lawyer, or pro athlete?"

None of the choices particularly appealed to A. He found it hard to really imagine being anything but L's successor. "Um, writer, I guess," A eventually replied.

"Really, not interested in being an athlete?" B joked.

"I'm allergic to physical activity," A shot back.

"Maybe you just haven't found a physical activity you enjoy, yet," B said, suggestively. A felt himself flush red again.

"That brings us to the next section! Romance and sex!" B declared. A let out a spluttering cough.

"Uh, what does that have to do with blood type?"

"Everything, there is even a compatibility chart in here," B said, and turned the book towards A so he could see. Sure enough there was a chat with different blood type combination, complete with percentages for how compatible the two types would be. B pulled the book away before A could really study what it said.

"This is ridiculous," A muttered, still flushing red. Sexuality and romance were subjects that B seemed to love torturing A with. A refused to give any details about his non-existent love life, but it was clear through his teasing that B knew A was a nineteen year old virgin, who had never so much as shared a real kiss with anyone. The subject was made even more awkward for A due to his inexplicable and extremely unhealthy obsession with and attraction to B.

"Would you say you find expressing your feelings easy?"

"Not really, no," A mumbled in reply. Why was he still going along with this? He could end this at any time. He could force B back in his room, bolt the thick security door shut and go back to work. A could reach over and hit any of the panic buttons that were hidden all throughout the apartment, triggering B's cuff and knocking him out. There was really no reason to sit here and play this embarrassing game with a convicted murderer.

Well, expect the fact that A was a self-confessed, messed up, twisted masochist that thoroughly enjoyed playing these dangerous and humiliating games with B, and that he was always secretly hoping that things would go too far.

"Aw, 'Lexi is shy," B teased.

"Don't call me that," A shot back automatically.

"It's okay, you just have to find someone who is dominant to make that first move," B continued, giving A a look that strongly suggested B was just that person.

"Shut up," A snapped.

B laughed. "Okay, next question. In sexual situations, would you say you enjoy being on top?"

A choked on his own saliva. "W-what?!"

"Would you say you enjoy being on top, or in control?" B asked again. His voice was calm and even, making A's spluttering even more embarrassing.

"Well, um…" A trailed off.

"If you lack any real life experience, you can always just go with what you fantasise about," B said, voice the perfect imitation of someone trying to be helpful.

A glared at B, who was grinning from ear to ear.

"Um, I would say I am a more submissive person," A finally managed.

"Nothing to be ashamed of, loads of people are submissive both in life and bed," B replied, cheerful.

"What about you?" A questioned suddenly.

"Me? Do you even need to ask? I am dominant in life and otherwise," B said with pride.

A's mind quickly supplied A with a number of vivid scenarios of B being dominant, many of which included a very submissive A under him. A cursed under his breath, trying to shake the images from his head.

"Hmm, I think we can skip the next question," B said, again glancing between A and the book.

"Why?"

"It deals with embarrassment in relation to sex and romance," B laughed and A hung his head, but didn't respond.

"Okay, what about soul mates and love at first sight? How do you feel about those?" B questioned.

"No to both. Well, sexual attraction can happen at first sight, but not love. And the idea of soul mates is a silly and rather depressing," A replied quickly, both glad and disappointed that the subject had shifted from away from sex and to romance.

"How unromantic of you," B commented. "How is the idea that there is someone out there who is your perfect match depressing?"

"Well, logistically, the world is a very large place, if there is such a thing as soul mates, what's the grantee that you will ever actually encounter that person? We as humans are limited to interacting with a very small portion of the human population."

"Ever the logical one, Alexander," B said, when A had finished.

A bristled at the sound of his name. "What did I say about using my name? I still don't even know how you figured it out," A scolded.

"Fine, I will stick to 'Lexi, then," B said with a shrug.

"I don't like that either."

"Then make me stop, 'Lexi," B taunted.

A let out an exasperated sigh. "Are we done with your personality quiz?"

"I think I have enough information to make an educated guess," B said with a nod.

"Okay, so what is my blood type, based on that lame personality assessment?" A asked.

B grinned, "Type A, of course." B seemed to find this hilarious and proceeded to let out a lough crackling laugh. A just rolled his eyes.

"This was a waste of time," he muttered.

"Oh come on, I think it fits you very well. Here let me read a bit about Type A," B said, amused. Before A could protest any further, B launched into a monologue about Type A personalities.

"Type A personalities appear cool and calm but are really filled with anxiety. They are thoughtful and plan and research extensively, rather than going with intuition when making decisions. Type A's are sensible and serious. They are often introverted and bottle up their emotions. In love they usually fail at expressing their feelings, but fall in love deeply and are very committed to satisfying their partner." B finished and closed the book dramatically.

"Those are vague characteristics that could apply to anyone," A scoffed.

"So serious, just like a Type A," B teased.

"Well what about you! Give me the book, I will quiz you!" A reached out for the book. B seemed surprised, but handed the book over.

A huffed and opened the book, flicking through the pages. As he looked down at the mess of Japanese he quickly remembered that his knowledge of the language was lacking. He could read this, sure, if he was given about two hours and a dictionary. He flushed and looked up at B, who was chuckling.

"Need to work on your Japanese, huh?"

"Shut up." A tossed the book back to B. "I don't have the time."

"Languages are important. Isn't L working a case in Japan as we speak? How do you expect to be L one day when you can't translate a lame pop psychology book?"

"How do you know what L is doing?" A demanded. "Have you been stealing my case files again?"

"Don't have to steal them when they are on display," B said, motioning to the pile of papers A was sitting in.

"I warned you once about that!"

"After I helped you on a case you were stuck on. But back to the languages, if you need help translating, I am very much free." B said, idly picking up a near-by sheet of paper.

A snatched the paper away from B. "I am completely fluent in seven languages, including Latin, thank you very much. And I have a working comprehension of about six more. I don't need your help!"

"Latin is a dead language, I don't think it counts."

"I am very close to locking you back in the cell downstairs," A growled.

B just smirked. "Gotta watch bottling those emotions."

"You are the most frustrating, impossible individual on the face of the planet, I swear to god," A grumbled, and moved to shuffle the surrounding case files together. He knew he needed to be more careful about the sensitive information with B hanging around, but this was just the way he worked.

"And yet you chose to keep me as your personal pet," B said with a condescending laugh.

"Would you rather be back prison? Or the mental hospital?" A shot back.

"Those places are too easy, too boring. Besides, I'd be out in a matter of days."

"What about back in your cage downstairs, because that can seriously be arranged," A snapped. He stood up, now holding a haphazard pile of papers.

"Oh, I wouldn't care," B said, following A into a standing position. "But you would. I remember those first months. You did everything but sleep in front of my cell." B advanced on A, knocking the files from his hand and towering over the smaller man. A let out an angry shout before B moved in even closer. "You need me," B said pushing A back onto the nearby sofa. B followed A down, leaning in close.

"Say it, Alexander, say you need me," B hissed in A's ear.

"I… I don't need anyone," A said defiantly. B laughed and his hand moved to A's throat, grasping just tight enough to be a threat. A's eyes flared. He knew there were people monitoring on the surveillance cameras at all time, and should B cross any line, they could hit a panic button to disable the murderer. Still, the pressure on his throat made A's heart jump, despite the knowledge that he was actually completely safe.

"You are so good at lying to yourself," B muttered and tightened his grip.

"Watch it, Beyond," A gasped, and his eyes flicked to the camera in the corner.

B let him go and backed away with his hands raised, showing his innocence. A coughed, but stayed sprawled on the sofa

"Your friends certainly let me get away with a lot, probably a lot more than I should," B commented, motioning to the camera.

A didn't say anything. B was right, though. After the first few weeks in which B ended up shocked, or outright knocked unconscious too many times to count, A had told his security team to disregard B's more minor acts of violence, and to only press the panic switch if A's life seemed to be in grave danger. A had claimed it was for B's own safety, as it was dangerous to knock him out so frequently, when in reality it was purely selfish reasons. It wasn't like he could really explain to the head of his security team that he liked it when a convicted murderer choked him, punched him, and pushed him around.

B bent down and retrieved his book from the floor. He flipped it open and started reading out a list of personality traits.

"Curious nature, can become irritable when things do not go their way, strive to be at the top of their fields, very goal oriented. Impulsive, relays mostly on intuition. Focuses in on one task at a time, not good multitaskers. Wild and open, but can be selfish, and irresponsible. In love they are honest, adventurous, dominant, and flirtatious, often having many partners." B finished and snapped the book shut.

"What was that?" A questioned.

"My personality type," B replied. He turned to leave, but A called after him.

"What type are you?"

B paused and turned to smile at A. "Type B, of course," he replied, before breaking out into a fit of laughter.

A collapsed further into the sofa, watching B disappear down the hallway. A leaned his head back and slowly counted to one hundred, trying to calm himself down. These incidents seemed to be happening more and more, and each time A was a left a trembling mess.

After counting and managing to slow his heart rate to a semi normal level A stood up from the sofa headed down the hall towards B's room. The room was fitted with a special, thick security door that A could close and lock from the outside, effectively making B's bedroom a cell. The door was currently cracked. A pulled it shut the rest of the way and locked B away. He then went to the large combination safe and grabbed a laptop. He booted it up and sent a quick message to Roger back at Wammy's, requesting any and all medical files they had on A and B, in particular, any records he had of their blood types.

Quick Note:

Everything about blood types and personalities I got from a few hours of research on the internet, and while I have to admit I am very much on A's side as far as the validity of blood types affecting personalities goes, I apologize for any mistakes.