This happens a few months after Sherlock and Molly first met, but a few months before John and Sherlock met. I know I should be writing the next chapter to Le Sacre du Printemps, but this idea was in mine heart as a burning fire shut up in my bones and I could not keep it shut.
And I got this idea from a picture on deviantart, Supreme by NamesroH, which shows Irene Adler and Sherlock Holmes dancing with masks on at a ball.
Sherlock Holmes was at St. Bartholomew's annual masquerade ball—he excepted the murderer of a florist Maria Gabby to be there—when he saw her. The glare from her golden mask had blinded him when he casually glanced in her direction. She was about three hundred yards away from him and was wearing a fixed dark blue and light blue one shouldered dress that was being held up by a silver binder clip that flowed off her body like water. She had short, curly muddy brown hair with diamond drop earrings, but he didn't know what her face looked like because she was wearing a full, expressionless, golden mask. But when she noticed him staring at her, she intently stared back at him, giving him her full attention even though a man was trying to talk to her. Even though her face was covered by the golden mask, her eyes were determined and sharp and matched his intensity.
They had been staring for almost a full minute when he started walking towards her. She noticed this and started walking away from him. He kept his eyes on her as she glided into an ocean of people, near the dance floor.
"Excuse me, excuse me", he muttered as he attempted to swim through. "Excuse me", he had lost sight of her and his brows furrowed in frustration. 'No Sherlock. Look for Gabby's murderer, don't allow distractions.' His face retook the look of determination when a slender hand gently took him by his arm and pulled him onto the dance floor.
When he glanced down at his dance partner, it was the woman. "Although, I'm flattered, I'm not that much of a dancer", he muttered into her ear, even though he was swaying with her—his left hand clutching hers and his right hand on the arch of her bottom—and they were receiving looks from the party guests.
"Then why are you still dancing with me, Mr. Holmes?" the woman purred. "And why did you just pull me closer when Dr. Walker looked at me with interest?" she asked as a blonde man examined her.
Sherlock frowned and then said, "What better cover when you're looking for a murderer than dancing with a beautiful woman?" he furrowed his brows in thought; he couldn't place her accent. 'Welsh? No, no. London area; a deliberate attempt to cover up a Manchester accent with a London accent.'
The woman laughed a small, amused laugh and lightly patted him on the back, "Oh, Mr. Holmes, don't try to overcome your shortcomings with flattery...you're going to have to do better than that", she whispered mockingly.
"You don't work here", he told her, coldly looking at her, "and don't bother to lie."
The woman laughed again, "Now, Mr. Holmes"—she looked at him too—"why in the world would I do that?"
"You want something from me", he said coldly, "everybody does." She continued to look at him, "People always lie to get what they want."
"You seem to know from experience", she said, her voice on an edge: dull but deadly. "Besides, when did you get a cynical view of the world?" she asked him in a light, flirty tone. "Obviously not from experience since you're usually the one lying"...she trailed off.
"I only lie because that's what people do", he said harshly.
"Yes", she said, nodding and avoiding his gaze, "but is the truth anymore interesting?" she looked up at him, pleasure in her eyes, as he tightened his grip on her hand. She glanced over his shoulder and the look in her eyes suddenly changed. "That man...over near the tulips", she said in a low voice motioning to a short, pudgy, penguin like man, "Dr. Eugene Bragg. He killed the florist...Maria Gabby."
"Yes, I see him", Sherlock muttered as he swayed around to catch a glimpse of him. "How can you tell? He doesn't have any relation with the victim."
"There was a crumpled, unused tissue found at the scene, hm?"
"Yes, yes", Sherlock nodded.
"And five shots were fired from a 9mm, but the police only found four casings, right?"
"Yes, yes."
"A witness said that she saw a suspicious looking man sneezing moments before her death", the woman paused, "It is a well-known fact that Dr. Bragg is allergic to tulips and Maria grew tulips—loved 'em and the majority of her shop sells tulips. Look at his face; his lymph nodes are unusually enlarged and he's sneezing, and yet he's spending a large amount of time near thetulips. Now why would someone with a tulip allergy be around tulips? Conclusion, he's searching for the fifth casing in the tulips before they're handed out at the end of the ball", the woman said quickly.
"And why?" Sherlock asked, with a bored tone.
"Maria and Dr. Bragg are recovering alcoholics and met at an AA meeting. Obviously, they had an affair and Bragg broke it off, but Maria wasn't going to let it end. She threatened to tell Bragg's wealthy wife about the affair and so Bragg killed Maria to shut her up", the woman looked at Sherlock, "It's all very obvious. All you have to do is find the casing, find the gun buried behind Bragg's house, and you're done."
"Well done", Sherlock sighed out.
"Yes, yes, I know", the woman said in an uninterested tone.
"Now, what do you want in return?"
The woman was silent for a moment before saying, "A dance...and to help", the woman stopped dancing and stepped back from Sherlock, "The casing should be in the pot of tulips nearest to the podium", she mumbled as Sherlock walked away, pushing his way through the crowd of dancers to the podium. He stuck his hand into the pot and pulled out a casing.
"9mm", Sherlock studied the casing and pulled out his phone to call Lestrade. "It's Sherlock", he muttered into the phone, "I know who killed Maria Gabby"...
After Lestrade had arrested Dr. Eugene Bragg, Sherlock attempted to search for the mysterious woman. He, instead, found Dr. Molly Hopper, in an unflattering flowery frock.
"Uh—congratulations, Sherlock, on solving the case", she stuttered out and pushing a lock of hair behind her ear.
"Yeah, yeah", he mumbled, looking over shoulder for the woman. "Have you seen a woman in a blue dress and golden mask?"
"What woman?" Molly's face and tone showed a hint of jealously, she then bit her bottom lip to recover herself, "There was no woman in a blue dress and with a golden mask."
"Okay, okay", Sherlock garbled and then strolled off, coldly.