Did I say murder?
Motive
Addiction has shown its ugly face in many ways throughout Sherlock's life. It would be safe for anyone to say he had an addictive personality and never would Sherlock deny this. As a child, he obsessed with small things. Observing and creating patterns, walls and walls of theories and understandings of the foot traffic patterns outside his bedroom window was his first addiction. Succeeding and exceeding expectations in school and competing against his brother was another. In high school, feeling was another addiction that almost killed him. The rush of alcohol was his first taste of poison, fed to him by his brother's friends in an attempt to find laughs out of the strange child's behavior. The feeling of the liquid taking over his body was irreplaceable for the kid who found it hard to feel what and how normal people felt.
Sherlock learned at a young age the bitter reality of chemical addiction. Previously, he was addicted to the natural high of obsession but the chemical takeover almost drove him to an early grave. He was truly stupid for that chase and Mycroft made sure to remind him of it whenever the opportunity of addiction rose again.
As cigarettes become less and less socially acceptable, and as Dr Watson reminded him of the dangers of every drag, new addictions were in high demand. This time an addiction that both John and Mycroft would not jump on him for was needed. Cases were not dependable, at least not legitimate case now that John went viral. Cases about cheating boyfriends or lying friends did nothing to stimulate Sherlock the way cocaine shifted his world or alcohol drifted his body.
When John dropped a small brown bag in front of him, Sherlock looked at him curiously. His first assumption, based on the sound it made as it fell and its contents was small plastic hotel liquors. Sherlock never went into the details of his addictive personality but surely Mycroft's big mouth probably mentioned something to John. The war doctor couldn't be that stupid, could he?
"What is this?" Sherlock asked quickly, refusing to touch the package presented to him. He turned slightly in his seat to see if the answer was on John's silent face. When John stared at him, his face unsure of how to answer the question, Sherlock followed with, "I'm not touching it."
"Don't be an idiot Sherlock," John said after a moment of silence. "Just open the bag."
"I'm not touching it," Sherlock repeated, silently scoffing at the idea of John calling him an idiot.
With a sigh, John quickly snatched the bag and dumped the contents in front of Sherlock. Several small boxes of varying colors but all the same sizes fell out. His eyes connected with John's again as he tried to explain. "They're ecigarettes."
"Why would you give me fake cigarettes?"
The same silent look of disbelief was on John's face. He made the motions to talk but snapped his mouth shut to reconsider. "Why?" he asked both of them. "Because you can't keep smoking those things. You're too smart for that, you know they're bad and I'm tired of reminding you."
Sherlock looked at the boxes laid in front of him a little more closely this time. "And you honestly think I have not thought about them before?"
"No," John said, "no, I figured you thought about them before. Now I'm going to make you use them, at least for a week. That's final."
"No," Sherlock said, sitting back, settled on the topic.
"Sher - you don't have any options with this, you're doing this for a week."
"No, I'm not."
"Yes, you are. I told you you have no say in this."
"Not doing it," he said with a small smile, pushing his seat back and walking away from John.
These kinds of gestures from John were not new to Sherlock. John, being the closed off man he was, expressed concern in odd ways - even for Sherlock's understanding of human behavior. Changing the bread to whole wheat or the vegetables to an organic variety was the way John communicated. That and expletives.
"Yes, you're doing it. You can't say no without trying it."
"And how do you plan to force me?" Sherlock asked from the fridge. John stared into the kitchen, mostly in disbelief of the situation unfolding in front of him.
"I choose not to reveal that information," John said, looking at the bag in his hands.
"Well, then I choose not to use those damned fake cigarettes." Sherlock returned to his seat with a water in hand. "Now, please remove these things."
John, out of frustration, picked one up and threw it at Sherlock's chest. "Do it yourself, you cunt," he said on his way out. John was smiling to himself, most likely thinking rude things about Sherlock.
Sherlock watched him until he could no longer see the man walk down the stairs and returned his attention to the packages in front of him. The door closed with an audible slam that shook the apartment. Quickly, Sherlock rose from his seat, rushed to his bedroom and pulled the pack of cigarettes from his bedside drawer. Every cigarette but one was snapped. A quick sniff of the last cigarette indicated it was dipped in some chemical. Knowing John's twisted mind, probably something that would light his bowels.
Sherlock smiled and threw the pack onto his bed and reached under the frame and grabbed another pack. They all shared the same familiar scent as the surviving stick in the last pack. That pack joined its brother on the bed.
Reaching into an old coat pocket in the back of his closet, Sherlock found another tampered pack of perfectly ruined cigarettes to join the collection on his bed.
With a sense of urgency, Sherlock's mind shot to his underwear drawer and to the pack that resided there. "I swear," he mumbled to himself as he rummaged through that drawer to find another fallen pack.
In frustration, Sherlock marched over to John's room and did a quick glance on what comforts he could ruin for John. The military man enjoyed a simple room that served the purpose it was paid for. A bed, his clothes … nothing else. Frustrated, Sherlock turned around and sat back in front of John's gift, planning the murder of John Watson once and for all.