The ingredients needed to knock someone unconscious were nothing very damning, and Sherlock had no problem picking them up at his local corner store. It was simple to mix together a powder that, when injested, caused one to pass out quickly. All Sherlock had to do was slip it into something and convince John to injest it.
Luckily for Sherlock, John quite fancied his morning coffee, something he hadn't missed since he moved in with Moriarty to their flat on Floral Street. All he'd need was to get it into his coffee and John would practically walk himself into the trunk of Sherlock's car. The anticipation of starting his new project kept Sherlock up in the night and by morning, he was practically itching to get out of the flat. He carefully parked his car just down the road, not a five minute walk from John's flat, and entered the cafe he frequented every morning. He sat and opened a newspaper, waiting for John to arrive. Soon enough John was walking through the door, stopping only to have a quick chat with a man outside. Sherlock approached the counter just before he did.
"I'll have a large coffee, black, with two sugars." Sherlock demanded rather than requested, then stepped to the side so John could order. He was close enough now that he could smell John's aftershave, cologne, and some other smoky scent, a mix that together created a scent unique enough he was sure he could pick it out of any crowd. He wondered if Moriarty could identify John's body by it.
"Can I have a large black coffee Mrs. Turner?" John was so different, so... normal, and yet unique. He smiled as he asked for a beverage he was paying for. Who does that, really?
"Of course dear, of course. On the house, your money's no good here John," The lady insisted, and John smiled even wider.
"You're a saint, Mrs. Turner, an honest to God saint."
There was silence at the front as she put on a pot large enough for both orders and settled herself about some other business while it was brewing. Neither John nor Sherlock spoke as they both watched Mrs. Turner go about her business until finally the long ding told them their coffee was done. She poured their cups, adding two sugars to one, then handed them the cups with smiles. Before she even spoke, Sherlock had subtly grabbed the wrong one and turned to go out the door, so Mrs. Turner spoke more to John than him.
"Thank you boys, and have a wonderful day at work. And John, please tell Jim that while I appreciate his thought process, it's really not condusive of sleep for gunshots to be going off in the next flat at 2 in the morning," Mrs. Hudson said as she smiled at him. Sherlock slipped a small, white powder into the coffee in his hand and mixed it ever so subtly.
"Oi, I think I might have grabbed your coffee by mistake," John said, pulling a face as he sipped the drink. Sherlock turned, pretending to sip from his own then making a similar grimace.
"I believe you are correct," Sherlock said as they switched drinks. He watched with satisfaction as John sipped the coffee and smiled.
"That's much better. Nothing but pure coffee for me, thanks anyways," John laughed, and Sherlock laughed with him.
"Yeah, I suppose I simply never got used to the taste," he said as they walked out together. "Besides, I find the sugar helps stimulate me, helps me think more clearly, if you know what I mean."
"I think I do. My flatmate Jim says the same thing all the time," he said as they walked along, then laughed as he commented "Although, he needs a lot more stimulation, apparently. I swear he dumps half a pound in. It's more sugar than coffee, honestly."
"I'm John, by the way. John Watson." He held out a hand to Sherlock and he took it.
"Gregory Baker. Pleased to meet you," he greeted. He could tell John was slowly feeling the effects of the drug. His normally graceful movements now seemed labored, and he was much more languid in his speech.
"Are you alright John, you're looking a bit pale? Perhaps you should sit down for a second." Sherlock opened the door to the car he'd parked here earlier and helped John inside. John mumbled something that might have been an agreement or maybe a protest, but it didn't matter as Sherlock shut the door and went around to the driver's side. By the time he'd gotten in the car, John was out cold.
They drove about half an hour to the abandoned office building Sherlock sometimes used as a storage facility, since it was in the middle of various other unused buildings and he wouldn't be noticed coming in and out. Inside, there was a room furnished only with a chair, handcuffs attached to either arm and the two front legs. Sherlock carried John to the chair and carefully placed him down, attatching the handcuffs to the appropriate limbs and then took off the backpack he had on. He went about setting the stage for when John eventually awakened.
Several hours later, John stirred. The first thing he noticed was the pounding in his head, causing him to squeeze his eyes further shut in protest. He realized his arms and back were both painfully stiff from the position he'd remained in far too long and he tried to stretch, and found he was not able to move his arms more than a few inches up before being stopped by the jerk of a set of handcuffs. Carefully, he opened his eyes. If he had looked around he would have realized it was dark outside the window beside him, meaning he had been unconscious at least the entire day and possibly more than one. He might have seen the mirror to the right of him, and if he had really examined it, he might have deduced it was a two-way mirror, with his captor standing on the other side watching him. John didn't look around, however, because he could not take his eyes off the wall in front of him.
Every inch of it was covered by pictures of dead people, mostly soldiers. Some were victims of cases he had worked on with Moriarty, others civilian casualities from Afghanistan. Some were badly deformed from injuries, others merely looked to be sleeping, about to arise momentarily. Their ages ranged from an elderly woman well into her eighties to a small baby, still clutched in its dead mother's arms. A child of no more than six or seven stared blankly back at him with dull blue eyes that should have shined with joy, and this picture hurt perhaps more than the others because he remembered the child so well, had been so very responsible for the boy's death.
"Padshah," he murmured, transfixed. Padshah had been a bright eyed, playful boy well known to the troops for bringing them his father's trade goods from the nearby town. He would play basketball with the troops and knew all of them by name. While Padshah was speaking with him one day, they had received word that a group of enemy soldiers were quickly approaching. Padshah had tried to run but John had stopped him, had pulled him to the side of the road and behind a rock.
"No, stay here. It's too dangerous to run. Stay here and hide and I'll protect you," John had told him. When the bomb was thrown, John seen Padshah's eyes widen and he tried to run towards the boy, jump in front of the bomb, but he was simply too far away. Padshah died knowing John had lied to him. If John had just let him leave...
"Recognize them, John? Maybe just a few. After all, there are so many, how could you possibly remember them all?" A voice asked from an intercom John hadn't noticed.
"How... what... who are you?" John sputtered, barely able to speak, though whether it was his dry throat or his shock that prevented intelligible speech, John couldn't be sure.
"Who am I, John? I think you might want to take another look at these pictures and ask yourself 'who are you?' You were a doctor John, you were supposed to help these people. Instead, you let them die. Are you a healer John, or an angel of death?" John looked frantically around as he tried to find something to focus on, struggling against his bonds. He found a camera on the right hand side of the room and he directed his anger at it.
"Who are you?! What do you want from me? What is all this?!" Sherlock chuckled.
"You're not asking the right questions, doctor. The question you should be asking is 'Are you going to kill me?' And the answer, my dear Watson, is almost certainly."