This is for the tumblr valentines day exchange, I got the plot 'poison in the tea' an tried to do my best :) hope you like it!

"New case, John. Female, mid forties. Meet me at the pathology, I'll tell you more then. SH"
The doctor groaned and slowly got out of bed, looking over at his alarm clock. 6:15 in the morning. The detective really didn't have any time measurement. But he was his closest friend, anyways. Part of him wished for a normal, calm life with his wife, in a small house with 2.5 children and a dog. Then again, he loved the thrilled the danger that his work got him into. His work, and Sherlock, who never forgot to remind him. Remind him that with his wife being an ex-assassin and his best man being a high functioning sociopath, he'd never fall out of that scheme.
Wife, partner for life... The words tasted weird on his lips along with Mary's name, untrue, like it didn't belong there. But he kept telling himself that it had been his choice, that he had wanted to marry her... Everything would fall back into place soon enough. It was just the shock about Sherlock getting in hospital and finding out about Mary's past.
He hurried up the stairs to the pathology building, and the taller man greeted him with a nod and just his presence woke him, made John's brain click back into working and into the job he loved.
„Details? Place, time and cause of death and I need to see the reports an corpse."
„Ah, there's the John I know. Was about time you got here. Let's go, Molly went home already but she left the reports for you."
John followed into the pathology, the only corpse around being the one of a lady, barely ten years older than him. She looked familiar, but he was unable to recall why. With a nod, he symbolized Sherlock to start.
„Abbott, Mathilda. Found in her living room chair, studio flat near the city centre. No signs of a robbery, the only thing close to her was a teacup. No poison in her body, no wounds or strangulation marks on her. Over all, a little mystery. The game, Doctor Watson, is on!"
„The game is on, Mister Holmes", John replied with a slight grin. „According to the state of her body, she died yesterday afternoon. The name... It seems familiar to me. Any motives for her death, possible suspects?"
Sherlock shook his head and thought for a moment.
„Nothing. No relations to other deaths, either. For now. You should probably call her daughter and husband, they're out of the city."
The doctor wordlessly started to walk through the hallway, deep in thought about where he could've seen the woman before.

The next victim was found in a hotel room, lying in bed with a bottle of vodka I'm his hand. After Molly's tests, the results were the same like they were with the first corpse. No wounds, no strangulation, no poison.
„Mike Smith, died twelve hours ago. The cleaner found him. Alcoholic probably, there was enough alcohol in his blood to make anyone pass out. Not enough to kill though. Again, no poison in his drink or anyone around, according to Molly's test results."
Sherlock took another look to the kitchen.
„No one has been inside this room with him. He stumbled through the door with the bottle in his hand, drunk to the point of passing out and fell on his bed to never wake up again. He was at the hotel bar. I guess we're looking for similarities first. Couldn't find anything in their police reports though.
The doctor's phone started vibrating in his pocket and Lestrade's voice bellowed through the phone.
„Watson, tell Sherlock there's another case fitting your scheme. If you want to look at the corpse, I expect you at Oxford Circus in ten minutes. Her name's Jessie King, she's the mother of a fifteen year old boy."
The taller man shook his head and John's eyes widened.
„We're not coming. I've got to check something. Sherlock, I just found the connection between the victims."
The detective frowned, expecting an answer as the phone went silent.
„Mrs Abbott once came to us because her husband went missing, Mike thought he had lost his car during a bar tour with friends. And Jessie King's son was the runaway boy. They were our clients. Declined ones, anyways. Question is, why would someone want to kill them?"
„Nice John, I never even thought of that. It explains a lot... We just need to wait for this experiment in the kitchen to finish and I'll have my theory proven."
He pointed over to the laboratory on the kitchen counter, then turned back to John, who was in obvious discomfort at the question he was about to ask.
„Sherlock... Who shot you?"
The detective tilted his head to the side, trying to analyze John's reasoning for the question.
„Oh well, it was the act of a professional. Aimed to kill, but not right away. A bit further to the left and it would've hit a bigger blood vessel, falling differently would've caused it to rip the vein and cause an inner bleeding that would've led to automatic death. Someone trained, the experience of many years of acting in secrecy and a long death list. And yes, I am talking about the person on your mind. Why did you ask just now?"
The doctor's voice sounded deep in thought, clouded with distraction.
„Someone who tried to get rid of you once would try it a second time. Pointing the blame for several deaths on you. I mean, why would you want people to think that you don't take cases because they're too silly for you. People would believe you killed them. But... Mary?"
The doctor gripped his chair to regain balance.
„My wife tried to kill my best man."
„well... Maybe this is the time to tell you that she actually succeeded. I was dead for a few seconds. But I'm alive... again. "
Something in the kitchen exploded, and Sherlock's head turned fast enough to make his curls fly from his cheeks and forehead.
„Point proven. We need to get to the pathology now. She will know that I do. You stay out if trouble and save me if there's need to do so. "

Sherlock's eyes were focused on the gun pressed to his chest, followed the silencer and up a slim arm to meet Mary's ice cold glance.
Molly's whimpering hurt in his ears.
„I didn't tell that I faked the test results, I promise! Just don't shoot him, please! Please!"
The two opponents ignored her.
„Well then, this is the final showdown, Mrs. Moriarty. Slowly killing poison... Of course we didn't find anything in the cups or vodka bottle. Nice move, could've worked. Nearly did. I'm sorry it didn't. Sorry about your precious little brother too. Didn't really mean to kill him, I never even touched the gun. I'm just glad that John doesn't have to see this, I don't think he'd want to live with a woman who shot the man he loves... Twice?"
She growled, never doubting that he told John about their little incident. He had to be gone, and that little Molly brat that was so loves truck would join him. The bullet clicked into place, the grim expression on her face not even twitching.
„Mary, put the gun down, now. I won't hesitate to shoot you if I need to."
The gun started to tremble in her hand as John's voice arose behind her, a colt pressed to the back of her head.
„John, you... You wouldn't! I'm your wife and he's just a pathetic wannabe detective, using him to help him solve crimes and nothing more. He uses you, and I love you! I just want to help you..."
Her fingers slowly lowered onto the trigger and John shook his head.
„Liar."
A gunshot echoed through the room, and everyone went silent.
The doctor's gun dropped to the floor as he watched the woman he had once loved fall to the floor. Sherlock let out a shaky breath and smiled.
„You know, for a moment I was worried that you'd let her shoot me. Thanks for not doing that though. I guess we got rid of another Moriarty then."
This was so much like the world's only consulting detective that John nearly laughed at the words. The look in his eyes told that he wasn't only glad about a Moriarty's death, but something else, too.
He leaned down to clumsily wrap an arm around his partner, inexperienced in showing support and unfamiliar with the feeling of John leaning into him, the feeling in his gut, but he instinctively knew what to do.
Lips pressed against the shorter mails temple and Sherlock's voice sounded just too sweet next to his ear.
„I'll always be there for you, John Watson."
And two mouths pulled up into a gentle smile as they met.

I know it's a little late, but it's still the 14th right? So, happy late valentines day :)