A string of murders had been taking place, all undoubtably linked. High class business men killed at different, but the same line, hotels. A case like this was what Sherlock had been hoping for, he had accepted the case and abruptly hung up on D.I Lestrade.
The case had taken him all around London looking at this and that, John had no idea how some places were even related. Their current stopping point was at Bart's hospital where Sherlock was analysing a specific type of hand soap to see if it could have been the murder weapon.
Sherlock was sitting at a table, his face squished up to a microscope, frustration obvious on his features. The door opened, he sighed and leant back into his chair.
Molly walked through balancing a tray of coffee and a box of glass slides for Sherlock's microscope, "Here is your coffee Sherlock!"
"Thank you Molly." Sherlock replied bitterly whilst nursing the hot mug he had just been given between his hands. "Who's your friend?"
John looked over to the door to see a young woman walk through, also holding a steaming mug. She was dressed smartly, fitted black trousers with a white shirt and sharp black blazer. She hung her black waist length coat, which she had had draped over her arm, on the coat stand next to the door. Her eyes darted to and from each person in the room, taking in her surroundings, she looked on edge but also very relaxed.
Molly slid the box of slides onto the table and looked at Sherlock, "Oh this is an old school friend! Her na-"
Gliding over to Sherlock the stranger stretched out her hand - which Sherlock took- and shook it. "The names (y/n) , and yourself?"
John and Molly raised their eyebrows but the detective merely smiled, "Sherlock, it's nice to meet you."
Sherlock rubbed his hands and pulled out a chair next to him, he gestured (y/n) to sit next to him. Molly glanced angrily at John (who just shrugged) jealousy written on her face. Whilst she sat he slid the microscope over to her.
"What do you think?"
(Y/n) laughed, "It wasn't the soap Sherlock."
Taken aback Sherlock replied, "What was it then?"
"Allergies. I'm surprised Doctor Watson didn't pick it up.'
John jumped in, "Sorry what didn't I pick up? And why is she now in on the case?"
"Don't be dense John, Miss..." Sherlock glanced over to (y/n).
"(Y/s/n)" smirking, you replied.
"Miss (y/s/n) is probably the least stupid person - apart from me- in this room."
(Y/n) laughs out loud, "I'll take that as a complement."
"Hmm, please do. Now sit down John. You too Molly, movement and stupidity is too much to handle."
The two who were standing pulled out a chair and sat down, both looking forlorn.
"Please continue (y/n)."
"Allergies, allergies with not too obvious symptoms. Nut allergies are a no go because they include swelling which would have been picked up by you instantly. No, this person is clever. All the men were here on business, 2-3 day trips. Meals being provided-"
Sherlock jumps up, "OF COURSE!" But he looks back down at her and seeing the harsh glare sits back down.
"Urm...sorry. Carry on."
She shakes her head, John and Molly stare at Sherlock looking surprised.
"Meals were being provided so people would mention their allergies so the cooks knew what to avoid. Our murderer then has a list of all of their guests allergies. A list of potential murder weapons...I'm sure you can now go find out how he used these allergies to kill each guest Mr Holmes."
Leaping up again, a huge grin on his face, "Yes! Yes! How did I not see it, it's brilliant. They're brilliant. You're brilliant!" Sherlock leaps over to her and takes her hand, pulling her up off the chair and across the room.
(Y/n) laughs as she is being pulled out the door, John and Molly have their jaws against the floor, "Sherlock what about John?! My coat is still in there and it's -1 at least out there!"
Pushing his coat into her hands and her down the hospitals stairs he babbles on about 'not enough time'. Both of them rush out the hospital doors and into a taxi, Sherlock's coat flapping at (y/n)'s heels.
3 months has passed since that night and (y/n) and Sherlock are as close as ever. Molly has got over the fact she and Sherlock aren't meant to be and John is relieved to have someone to distract Sherlock.
It was Christmas time and the Holmes parents were holding a party for the brothers, John and their +1's.
(Y/n) and John were sat on the sofa, chatting while Mycroft and Sherlock were out smoking.
"He adores you, you know that?" John suddenly said.
She smiles, "Yes I know that, and the fact I know that is enough. I don't need him to show it to me every day, he's not like that so it would be unfair to expect it of him."
John returns the smile, "Yes, I think that was Molly's problem. She expected him to change for her."
"Yes she did, but she still wasn't comfortable with Sherlock knowing everything about her. The first day I met him I walked in knowing he knew everything about me, I skipped all the 'boring stuff' and got to what Sherlock enjoyed."
Both of them smiled at each other, then turned to the sound of the opening door.
"(Y/n) (Y/n) (Y/n) ?!"
Smirking she replied, "Yes Sherlock?!"
He waved a Manila file underneath her nose, "The game is on!"
