A.N.: Thank you to everyone who reviewed and favourited/followed this story! It got a lot more attention than I was expecting...

Warnings: References to drug use and mental health issues, swearing, spoilers for the first series (and possibly the second series). Also, there is a lot of emphasis based on the theory of evolution in this chapter. I understand that people have differing views on evolution, but it is quite crucial to this story which it is why it has been included.

Disclaimer: Don't own Sherlock.


Chapter 2 – The Bond

It took John a week to read the book. By the time he had finished, he wanted to put a bullet in it.

He had known of Sherlock's true nature for about a year; the detective had told him of it just after the incident with Moriarty at the pool.

"You were willing to sacrifice yourself for me," he had said indifferently, "I think it only fair that I repay the favour in some way."

At the time, John hadn't known what to expect when the detective had shown him that there was a hidden compartment in the fridge, underneath a bag of ears preserved in something that smelled horribly of formaldehyde. He wasn't too surprised that it was filled with chilled blood bags – after the head, he didn't think he'd ever be surprised again. But when Sherlock had told him what they were for…

At first, he had thought that it was an experiment: trying to gauge the reaction of someone to this kind of news; although what the data collected could be used for, the doctor could only guess at.

The feeling that the reason for his telling him this was only for such 'innocent' purposes as an experiment began to dwindle when the detective offered to order a copious amount of Chinese – and pay for it. John had begun to feel slightly uneasy at this point.

What hadn't helped matters was that, even though they didn't have a case and Sherlock did eat in hiatus periods, the detective helped himself to a large plate of food and – over the course of their conversation – ate all of it. John had never seen so much food pass the detective's lips in one sitting.

"So… you're a vampire?" John had asked, trying to keep his voice light if only to reassure himself that of course it couldn't be true. This was a game, thought up by the detective to stave off his boredom.

"Yes," Sherlock had nodded simply, before stuffing an obscene amount of noodles into his mouth.

"Like, with fangs and everything?" John had chuckled, though he had a sneaking feeling that this was no laughing matter.

Sherlock swallowed his food and, in the same matter-of-fact tone, replied, "Yes. Would you like to see them?"

"Uh…" John had mumbled, his prawn dropping back onto his plate from between his chopsticks. "Sure. Why not?" He tried to sound dismissive, but his heart rate had increased significantly – Can he hear that? a part of him asked – and he could think of no way that Sherlock could fake fangs.

Sherlock prized his lips open slightly to reveal his teeth. They were all normal length; alright, his canines did appear a little sharper than most people's, but John was a doctor, not a dentist, how was he supposed to know if that was normal or not-

But then those canines began to elongate until they were about an inch and a half long.

John felt his eyes widen. "What… the…"

Sherlock retracted his fangs and went back to eating his Chinese, as though nothing had happened.

A million and one questions began whizzing around John's head, each one trying to be the first one to stumble out of his mouth in a rather undignified fashion. Yet in the end, he went with:

"Why are you telling me this?"

Sherlock looked up from his plate, slightly confused. "I told you," he explained. "What you did by the pool. That was… good. While we have to be wary of revealing ourselves to humans, I thought that it was time that you knew."

John felt as though his brain had been disconnected for a few moments. "So…" he began, and he found himself looking at the wall rather than at his flatmate, "you're a vampire?"

"Yes." Sherlock looked up at him, and John noticed that he seemed… uncomfortable. "How do you feel about that?"

John chuckled humourlessly. "Uh, I don't know, really. You know, all the experiments, the deductions, and now this? I don't know."

Sherlock lowered his chopsticks slowly down to his plate. He cleared his throat and asked, "Are you going to leave?"

John blinked at him. In all honesty, the thought had never crossed his mind. After all, what was waiting for him beyond Baker Street? Nightmares, a limp, and an empty blog… Surely if Sherlock had blood bags in the fridge, that meant that he wasn't dragging people off of the street, and something in his soldier instincts told John that the detective would never kill anyone – at least, not on purpose.

Sherlock Holmes: consulting detective, slight oddball, vampire. It fit so well, John was surprised he hadn't guessed it himself.

"No," he told him. The discomforted expression on Sherlock's face melted away. They ate in silence for a few moments, before the detective spoke again.

"Ask me anything."

John choked slightly on his prawn toast. "I'm sorry?" he asked, his voice thick with food.

"About my being a vampire," Sherlock elaborated. "Ask me anything."

John had stared in disbelief for a few moments, before the multitude of questions that had been lurking in the far corners of his mind began to spill out.

"How old are you?"

"Thirty-six."

"No, how old are you really?"

"Thirty-six. Despite what human fiction writers would have you believe, vampires are mortal. We age like humans and then we die."

"A mortal vampire? How boring."

Sherlock had smirked at this. "Isn't it?"

"When did you become a vampire?"

"I was born one. Vampires cannot be made. My mother was a vampire, my father was a human. There was a fifty per cent chance I would be human. I wasn't."

"Is Mycroft a vampire?"

"Yes."

"Does anyone else know? Human, I mean?"

"Yes. Anthea found out shortly after she started working for Mycroft. Lestrade, when I was detoxing."

"Do you drink from humans?"

"I have done. Mostly I drink from blood bags. It is not as satisfying, but it is safer."

"For you or the person you're feeding from?"

"Both. I have never come close to killing anyone, but I would rather not accidentally drink blood laced with cocaine. It would put me 'back to square one'."

"Is this the reason you hardly sleep?"

"No. I don't sleep because my mind is too fast."

"Are all vampires as brilliant as you?"

Another smirk. "No. That remains… a family trait."

"You eat human food as well, though. How is that possible?"

"Vampire DNA is similar enough to that of humans that we can digest the same food. It is simply not as nutritious as blood. We could eat only human food but would die of malnutrition."

The conversation lasted long into the night – much long after the plates of Chinese food had been cleared. By the time John went to bed that night, he had accepted the latest eccentricity of his flatmate's.

Sherlock's being a vampire had never really got in the way of anything before now. He had his blood bags, and most of the time it went unspoken of.

Now, however, the book had turned up.

Oh, how John wanted to shoot it.

First, there had been the title: 'Explaining the Concept to Your Human'.

'Your Human'.

He had dismissed this, for it was only the title; it was clear, concise, and said everything that needed to be said about the contents of the book. He read in spite of the fact that he refused to be regarded as the 'property' of a vampire simply because he had been born a human.

Yet as he read, it only got worse. The book was, perhaps, one of the most patronising volumes he had ever read. It repeated the most basic of concepts several times, as though the writer believed humans incapable of retaining such information from one page to another, and was condescending even in its language.

The book had started simply enough; it explained the basics of vampires that John already knew. The concept that the book actually referred to in its title – the concept of a 'volens' – was not mentioned until page 3; and the definition was enough to make John's blood boil.

A volens (literally, 'willing') is the human companion of a vampire who willingly lets that vampire feed off of them.

He had almost put the book down. Sherlock wanted him to do what? Why, after all this time, had he suddenly decided to ask this of him? Had the blood bags become too boring? And why had he used this infuriating book to do it?

The book continued along the lines of a history lesson on the development of this 'affinity', as the book described the vampire/volens relationship.

It is the accepted scientific theory that vampires evolved at the same time as humans, separated by a genetic mutation. This has led to a developed relationship between the two species as they are, in terms of social interaction, almost completely the same. Inter-species friendships and even romantic relationships are common, and this has aided the emergence of the more intimate affinity of the volens concept. (page 8)

After the history lesson, it moved on to more descriptive purposes of the 'affinity':

In terms of creating the vampire/volens affinity, the first feeding is the most important. In this feeding, a bond is created between the vampire and the human which inextricably links the two together. As the more sensitive of the two, the vampire is more aware of the bond than the human. In some reported cases, the human has been completely unaware of it. As a result, this bond, from the point of view of the vampire, cannot be broken, even if the affinity ends. (page 16)

This only seemed to fuel to doctor's anger. A bond? That couldn't be broken? Sherlock was barely comfortable admitting that they were friends; why would he want to create an extra bond between them? Yet this passage was not all the book had to say about the bond, and what it had to say next chilled John to his very core.

The bond – as with all aspects of the affinity – is more dangerous for the vampire than for the human. Vampires have heightened senses in every way, including the feelings of emotion. Because of this, many vampires choose to distance themselves from emotion as much as possible. However, in the affinity it is unavoidable, and the bond can even force the vampire to fall in love with their volens. Whether this is requited or not is based purely on the human's own feelings, due to the bond affecting the vampire more than the human. This side-effect is, however, by no means definite. The number of recorded cases of a vampire falling in love with their volens purely because of the bond is approximately 5% of all recorded cases of vampires with volens. (page 28)

The bond, as a concept, was truly terrifying. What would happen to their relationship if Sherlock was to fall prey to the side-effects? The book had said that it only happened five per cent of the time, but that was only in recorded cases. How many unrecorded cases were there?

Nevertheless, John read on…

The evolution of vampires is very similar to that of humans. Vampire DNA only differs from human DNA by 0.5%, which has led to a relationship between the two which is more respectful, considerate and morally-grounded than simply that of predator and prey. (Indeed, some anthropologists argue that vampires and humans are, in fact, part of the same species, as they can produce fertile offspring with each other.) As a result, the human in the affinity is actually the most powerful in terms of influencing the parameters of the relationship. The volens can refuse blood to the vampire even after the bond has been established – for they are only a volens if blood is given willingly, even after the initial feeding. Furthermore, a vampire would never wish to harm their volens. It has become etiquette over the past few hundred years for vampires and volens to hold hands during feedings, for the express purpose of the human using this contact to alert the vampire of when they wish the feeding to stop. (page 31)

Being in control certainly appealed, but holding hands? How did Sherlock think that either of them would be comfortable with that? Where had this idea come from?

John finished the book just before he went to bed. He could hear Sherlock plucking at his violin downstairs. He considered going down there to shout at the detective. Then he decided that after a monstrous day at the surgery, he was far too tired to get into an argument right now, and opted to shout at him in the morning.

However, most annoyingly, by the time he woke up the next morning it seemed like a good idea.

When the diamante case had finished, John was sure that Sherlock's hunger had almost killed him. He had had a sickly pallor and looked incredibly thin. John had always assumed that Sherlock just stayed away from human food while on a case, but it would seem that he starved himself completely. From what John knew about vampires, this was even more dangerous than if he was a human starving himself, for it could cause him to attack someone. Drain them. Kill them.

When Sherlock had disappeared and returned with the glow of a vampire who had just fed – and fed well – John had no qualms admitting that he seriously thought his flatmate had killed someone. Relief like no other had taken over him when the detective told him that he had merely raided Mycroft's blood bag supply.

This incident – along with the book – made John think. Did Sherlock starve himself in this way every time they had a case? What if they had a case that lasted a month, or longer? Sherlock wouldn't be able to go that long without blood, not without coming close to dying or taking the life of another.

"One day we'll be standing around a body and Sherlock Holmes will be the one who put it there."

The words came back to John from all that time ago. Donovan thought it would be because Sherlock was a psychopath – even though he wasn't a psychopath, he was a high functioning sociopath – but it wouldn't: it would be because he was hungry.

When John padded down the stairs the next morning, Sherlock was reading Mrs Hudson's paper at the table. He had not mentioned the book since he had given it to the doctor; did he even know that John had finished it?

"Good morning," John greeted the back of his flatmate's head. He got a similar, polite reply. "Coffee?" he asked as he headed for the kitchen.

There was a ruffle of paper as Sherlock turned the page. "Black, two sugars."

Maybe it was just John's imagination, but there seemed to be an awkward air in the flat. Everything was too quiet, so quiet it almost seemed loud…

John placed the mug of coffee on the table in front of Sherlock, who nodded in thanks, not looking up from his newspaper. John sat in the other chair to the table, and the silence continued. After a few moments of the agonising lull, Sherlock spoke.

"You read the book."

John didn't bother to ask how he knew. He cleared his throat. "Yes."

Sherlock slowly lowered his newspaper to the table, and he had the same uncomfortable look he had had when he thought that his being a vampire would prompt John to leave. "And?"

John sighed. "I don't know. I just…" He took a gulp of tea while he pondered what to say next. "Why now?"

Sherlock shifted slightly. "It has been… alerted to me that my starving myself while on a case is… not a good idea."

"Ha," John breathed humourlessly. "No, not really. Who told you this?"

"Mycroft."

Ah. Of course. The whole thing reeked of Mycroft.

"And…" the doctor began, trying to decide whether he would be out of line to ask the question on his mind. "Does he have a… volens?"

Sherlock did not answer straight away. "Yes." John nodded in understanding, sitting back in his chair and staring at the floor without really seeing it. "You don't have to accept," Sherlock was saying hurriedly. "It's just…" But, for the first time that John could remember, he appeared speechless.

John turned to his flatmate, but his gaze was still fixed down at the floor. "Did you know about the bond?" he asked, forcing himself to meet Sherlock's eyes. The detective looked distinctly discomforted.

"Yes," he said slowly. "But it's a mere side-effect. It wouldn't affect you-"

"But what if it did?" John asked, his voice raising. All his objections from the previous night were coming to the fore. "How would that affect our friendship?"

"John…" Sherlock began, almost desperately.

"Just… just answer me one thing," John interrupted, holding a hand up to silence his flatmate. "This… side-effect." He licked his lips nervously. "Did it happen to Mycroft?"

Sherlock paused. He opened his mouth and closed it again. He cleared his throat. "Yes."

They lapsed into silence again, staring at each other from opposite sides of the table. John didn't know what to think. He couldn't bear the thought of being on the receiving end of such coerced feelings. Yet at the same time, he couldn't forget that image of a starved Sherlock out of his head. He couldn't let someone die because the detective had finished all his blood bags and refused to get any more until the case he was working on was completed.

The silence was broken by the doctor's sigh. "I'll think about it."

The troubled air that had filled the flat dissipated at once, and both seemed more relaxed.

"Thank you," Sherlock nodded, picking up his newspaper once more.

~{G}~

The door slammed shut behind him. John was in a bad mood. All of his appointments that day seemed to have been for children, and only three of them had the decency to be civil. Three threw tantrums – one of which had resulted in him getting kicked in the stomach – two simply would not cooperate, and a little girl who seemed to have diagnosed herself by looking up her symptoms on her mother's smart phone spent the entire appointment telling him all about how her pony was getting too big for her.

"Oh, it's no trouble, of course," she had 'reassured' him in her annoying I'm-better-than-you tone of voice. "Father will buy me another one, and Sandwich can be sold on."

Who named a pony Sandwich anyway?

In all the horror of all the children, he had almost forgotten about the book, and the proposition, and the fight with his flatmate from that morning. Yet all of it came crashing back to him as he entered the flat and found the aforementioned flatmate draped across the sofa.

Sherlock made no attempt to acknowledge John's arrival, but that was really nothing new. John offered him a polite greeting, silently hoping that the vampire would not mention the word 'volens' to him right now. A part of him felt that he need not hope at all: Sherlock would not ask him unless he mentioned it first.

John went to remove his jacket, when he heard his phone trill. Sighing, he retrieved it from his pocket and checked the text.

Outside. – Mycroft Holmes

John stared hatefully at the text for a few moments. Did he get no rest? All he wanted was to take off his jacket and shoes, make a cup of tea…

"The car is waiting."

John jumped at the sound of his flatmate's baritone drawl. It was emotionless as always, but somehow dulled. Deprived of even that spark that made him sound alive.

"Black. Unmarked. Bigger than usual. Three seats in the back instead of two."

For the second time that day, John did not ask Sherlock how he knew all of this. "Do you have to come, if there are three seats?"

Sherlock shook his head and gestured to his phone. "No text."

John's phone vibrated again.

Now, if you please. – Mycroft Holmes

John sighed and tucked his phone away. He turned to leave, bidding Sherlock farewell. He did not get a reply.

The car sat neatly parked outside the building; large, black, unmarked as always. Sherlock had been right – it was bigger than usual; there were three seats in the back instead of two. Who else was Mycroft picking up? The windows were still blacked out, and he couldn't see inside; perhaps the mystery third person was already in the car?

John opened the door – for there was no one to do it for him; another odd sign – and slipped into the leather seat, shutting the door behind him.

"I suppose there's no point asking where we're-" He turned to the left, expecting to see Anthea sitting there typing frantically on her BlackBerry, ignoring him, and – possibly – the third mystery person.

The sight that greeted him instead would have made him stumble backwards, out of the car (slamming the door shut behind him), back through the front door, up the stairs and into the flat – preferably to flop unimpressively into his favourite chair – if said sight was one that he could actually tear his eyes away from.

Anthea was indeed sitting next to him, but she had, for once, abandoned her BlackBerry – the phone sat idly on the leather between her and John. Yet she had another sitting next to her – or perhaps 'across her' was a more accurate description – and Mycroft's fangs embedded in her throat.

Nevertheless, she didn't seem too bothered. Her head was resting back on the headrest, and she was staring at the roof of the car as though it was the most interesting thing in the world.

He stared dumbstruck for a few moments, his breathing quickened as he got over the shock of such an unexpected sight. Yet as time passed, astonishment began to become boring, and he let his eyes wander around the scene before him.

Anthea's elbow was on her knee, her hand clasped around Mycroft's; as it had been described in the book. John suddenly realised that the book hadn't explained how this was supposed to end feedings. He supposed he would find out now. As he watched, Mycroft's jaw clenched; he guessed that the vampire's fangs had dug just that little bit deeper. Anthea gasped, her eyes closing, but she still didn't seem to be in pain. A few seconds later, she reached up with her free hand and curled her fingers into Mycroft's – admittedly short, but nevertheless lush – locks.

All of a sudden, the colour drained from her cheeks, and John guessed that she couldn't afford to lose too much more blood. She squeezed Mycroft's hand as hard as she possibly could, her knuckles turning white.

The vampire drew back slowly, and John caught a glimpse of his long fangs, smooth and usually pearly white; they were now a gleaming shade of crimson. He ran his tongue along the still-bleeding punctures so that they healed.

The elder Holmes sat back, and Anthea picked up her BlackBerry and began emailing/texting/whatever-she-did-on-that-bloody-t hing again.

"Good evening, Dr Watson," Mycroft greeted.

John blinked. After such a display, how did the older man slip into something so seamlessly… human? He was acting as though nothing had just happened.

"Er…" he began, unsure of how to react. Mycroft nodded at the driver and the car began to pull away. A plastic bag with bandages in it was tossed over Anthea and landed in John's lap.

"You wouldn't mind covering the marks, would you?"

"Why me?"

"I'm not a doctor."

Scowling, John ripped opened the bandage. It was a simple piece of cloth made adhesive on one side – like a giant plaster – big enough to cover the two angry red marks on Anthea's neck. She made no acknowledgement of his presence as he carefully placed the bandage on her skin, positioning it carefully so that it met its purpose but so that it was discreet.

John took the opportunity to glance at her phone, to see what was so interesting on her BlackBerry that she seemed to remain oblivious to her entire surroundings. He expected it was some form of BBM or instant messenger.

It wasn't.

It was a game that looked suspiciously like Mario: a little character was responding to her typing, running around and jumping over little platforms, collecting coins and whatnot.

Thinking that this day couldn't get any weirder, he smoothed the bandage over her neck and sat back in his seat. Unable to see Mycroft because Anthea was in the way, John caught his eye in the rear view mirror.

"May ask what the point of that was?" he sighed, though he didn't expect to receive an answer. Indeed, he was met only with the older man's twinkling eyes.

The car drove for about half an hour, in a silence that John found incredibly uncomfortable. It pulled up outside a large, impressive building that the doctor had only been to once: the building that held Mycroft's office.

"That's not his real office," Sherlock had told him. "His real one is five miles away from that."

The silence continued as he was led to the fake office – John elected to not say anything about knowing that it was fake – and he was asked to sit down at the seat before the wooden desk in the dark room.

"I suppose there was a reason for that display?" John asked impatiently. It had been a long day. He was not in the mood for any Holmes cryptic bullshit.

"Of course," Mycroft nodded, taking seat on the other side of the desk. "I understand that my brother has asked you to be his volens?"

John sighed. "Yes, and he told me it was your idea," He said plainly. He really was not in the mood. "When did you tell him to ask me?"

"After the diamante case," Mycroft explained, "he came to my office half-dead and drank all my blood. About twenty pints' worth."

The irritation John felt melted away. "Twenty?" he asked. Mycroft nodded. "He could have-"

"Killed someone. Yes, I know." Mycroft shifted uncomfortably in his seat. "You are having reservations about agreeing to the proposition."

John let out a humourless chuckle. "Well, you know…" John was finding it difficult to remember any of his doubts about the arrangement under Mycroft's gaze. "It's just… weird."

Mycroft sighed. "My brother… is a sociopath. He has, in many ways, handled this in the worst way possible. Am I right in understanding that he bought you a book to explain the concept?"

"Uh, yeah," John nodded, a little glad that Mycroft thought the book was weird as well. "Yeah, he did."

Mycroft smiled a little. "I'm sorry. I should have known that he would be so tactless."

John chuckled slightly, before he realised that the subject had been changed. "You still haven't answered my question."

"Oh?" Mycroft blinked.

"What was the point of that display?" John pointed his thumb over his shoulder at the door.

Mycroft smirked and sat back in his chair. "The book Sherlock gave you is idiotic. While explaining the basics of the concept, it does not relate what it is actually like to have a volens. Or, as would be useful to you, what it is like to be one. It does not explain, for example, that it does not hurt; which is one of things I am assuming you are concerned about?"

"Well, I-" John tried to protest, but Mycroft carried on regardless.

"It also puts too much importance on the bond," he explained.

John leaned forward. "Really? I think the bond is quite important." He looked over his shoulder at the door and back again. "I'm guessing this room is sound-proofed?" Mycroft nodded. John lowered his voice anyway. "Does she know?"

Mycroft did not answer straight away; he looked extremely discomforted. "Know what?"

"About the bond," John pressed. "About the fact that you're-"

"No," Mycroft held up his hand to silence the doctor, closing his eyes. He looked as though he was in pain. "She doesn't know." He lowered his hand to his desk, but when he opened his eyes, he wouldn't look at John. "And I would ask that it remain that way."

"I can't let that happen to Sherlock," John hissed.

"It won't," Mycroft said simply.

"You don't know that!" John shouted, almost standing up a little.

A moment passed in quietness.

Mycroft finally looked at John again.

"You saw him after the diamante case." It wasn't a question. "How did he look to you? In your… professional opinion?"

"My professional opinion?" John chuckled. "I studied humans at Bart's, not vampires! I don't know anything about-"

"Nevertheless," Mycroft interrupted. "How did he look to you?"

John sighed and sat back in his chair, staring at the window as he thought back. "Hungry," he began, his voice still holding a slight hint of spite. "Pale. His cheekbones were quite prominent, but they're always like that. He had bags under his eyes. I suppose his clothes were a little baggy. And he leaned against a wall when he thought no one was looking…" He trailed off.

"And then he came to my office and drank twenty pints of blood," Mycroft finished softly.

"Fuck," John breathed. He looked from the window to Mycroft.

Mycroft took a breath before speaking again. "On the second occasion on which we met, you questioned the legitimacy of my concern. I assured you of it. I knew by this point that you cared for him as well. And, in that sense, we are on the same page."

The door behind John opened. "Sir?" Anthea asked. John guessed that there was a button underneath the desk that called her in, and that the vampire had pressed it without the doctor noticing. Mycroft stood, gesturing for John to do the same.

"You don't have to accept," the elder Holmes told him, the corner of his mouth twitching. "But I think you should."

John nodded a goodbye as Anthea led him out of the fake office. When the door clicked shut, she was holding a card out to him.

"Wha-?" he asked, taking it from her. It had two sentences on it:

The Dog and Duck, Bateman Street. Tomorrow, 3pm.