Molly swatted at the fly that had decided the lab at St. Barts would be its new home for the time being. The consistent buzzing had become so aggravating that by the time a certain tall and lanky detective barreled through the doors, Molly's patience had run dry.

"Male, preferably 26-32 years old, but I can be-" Sherlock's sly grin vanished from his face as he saw Molly standing ten feet away with her hair slightly pulled out of her ponytail and her usual pink blush now sporting an intense vermillion.

"Sherlock." She greeted him with a hint of annoyance laced in her voice and turned back away from him with a whip of her frazzled ponytail.

"Bad day?" he asked. He was aiming for caring, but it came out bitter and sarcastic.

Molly laughed indignantly and Sherlock had the feeling she still didn't find the situation funny.

"I sort of have a lot going on right now, Sherlock. So whatever it is," she let out a sigh. Maybe she was being too hard on him.

"I'd suggest going a bit lighter on your make-up next time," he jabbed while motioning to his cheek.

Or not. "Go get yourself… A coffee or something. Give me like ten minutes, okay?"

He looked like he was ready for a rebuttal, but she turned away from him before he had a chance and decided a refreshment from the café across the street might better suffice.

The moment the double doors swung closed, Molly started ruffling through the cupboards underneath the counters. She didn't know what she was looking for particularly, but she'd know it when she saw it.

Finally, Molly discovered a small triangle with mesh in between the metal beams in a drawer beside the sink. She shrugged and took out a couple. Looking over her shoulder at the door again, she couldn't be too careful, she checked to make sure no one was coming. Once satisfied, she readied herself with one of the triangles in each hand and pulled herself on top of the counter.

The pesky little bugger sat chilling underneath one of the hanging fluorescents without a care in the world. A mischievous grin spread over Molly's face and she encroached upon the fly like a lion stalking its prey. With one sudden swoop, Molly trapped the bug in between her mesh triangles. A proud jeer escaped her lips, but it was without cause. Once she turned to step down from the counter, she realized the fatal flaw in her plan. What now?

Carefully she transferred the triangle from her left hand to her right to use her free hand for balance. When her front foot tried to find the stool to step down onto, everything came crashing down. To save herself over the trapped fly, the triangles clutched in her left hand dropped and clattered to the ground, releasing the fly. Molly found solace in the realization that her body still remained in one piece, but her pesky problem was still on the loose.

Three tries later with the triangles resulted in two more bruises to her hands and knees and one fly still on the… fly. She was tired of her safe approach and she had the feeling that the next time she tried, Sherlock would just happen to stroll in sipping his coffee casually and she would be on the floor in a sputtering mess.

"Time to see what's in the back room."

The storage room lit up like a lightning strike during a dark storm. Her eyes took a second to adjust before scanning the various instruments inside. There were extras of everything from test tubes to gloves, flasks and miscellaneous glassware. In the far corner was a tall tube of helium and another unidentified smaller tube beside it. Death by modified atmosphere could kill the fly, but she pushed away the thought when she realized that the process would most likely endanger herself as well. She was ready to leave when her foot kicked a small canister causing it to fall to the ground with a thud.

"Huh?" she thought aloud. A thick tube made of a dark canvas material branched off of the top until it ended with a pin about one centimeter in diameter. The writing on the original can was partially removed, but something told her exactly what it was.

As she exited the room and turned off the lights, a slow blaze of fire flared up in front of Molly's face.

"Where are you, you stupid bugger?" she yelled, holding the portable flame in front of her.

Molly was halfway across the room, when she heard the undeniable soft tap of a coffee cup hitting metal.

"Molly…"

Molly turned to meet Sherlock's eyes –a look of bewilderment flashing behind them, hiding… something.

"Never pegged you for a pyro," he stated with a hint of amusement in his voice.

"There was this… fly," she replied –her sentence dying by the time it neared the final word.

"Wouldn't want to be around if it was say… a wasp or god forbid, a spider." He smiled and held out a coffee. "I bought an extra. Much better than what they try to pass off as a good brew here."

He placed her cup next to his own as his eye flickered between Molly and the still lit flame.

"Thanks," she said half-heartedly. The flame died down before going out completely.

"You looked stressed earlier," he replied trying to come up with an excuse for his generosity. "Obviously for good reason."

The fly flew by his face with perfect timing and he swatted haphazardly at it.

"It really got on my nerves, you see," she said. Her eyes locked onto his and a small grin crawled onto her face.

His feet began carrying him closer to her, as if on their own accord. "Understandable." He shrugged nodding along.

"I had much less severe methods previously. They just weren't working."

"Oh, I know," he chuckled and reached down to hold her right arm up, revealing dirt marks on the underside of her lab coat.

'When had he gotten that close?' She wondered as his eyes left her arms and landed on her backside.

"Fell from the… countertop?" he asked, knowing very well the cause of the scuff marks on the back of her coat.

Molly unconsciously touched her backside and blushed.

"Well, yes."

"And when it didn't work, you upgraded to fire?" he was having trouble containing his amusement now and the whites of his teeth were peeking through his meek smile.

"Naturally," she supplied, smiling up at him.

"How fitting. May I see?" He held his hand out for the canister.

"Yeah, yeah." Molly steadied her voice and handed it over to him.

Sherlock took the can unceremoniously and looked it over, switching it from one hand to the next.

"May I ask what you need it for?" Molly looked up at him skeptically.

Sherlock chuckled. "Oh, I don't." He set the can down with a clink on the tabletop. "I just needed to make sure you weren't going to drop it."

Molly wanted to ask why she would have dropped it, when Sherlock hands flew to the sides of her head and pulled her up into a kiss.

A silenced 'oh' escaped her lips before her hands reciprocated his actions with the pads of her fingers smoothing down the dark curls on his head.

Just as quickly as he had gone in, he was pulling back. They met, eye-to-eye, trying to read each other.

Arousal. He was hiding arousal, Molly decided.

It was her turn to find his lips this time and she did so with such force, that it pushed Sherlock backwards against her stepping stool. Unable to detangle his hands from her hair in time, the two fell to the floor gracelessly.

"Sorry," Molly squeaked, forcing a nervous smile.

Sherlock didn't seem to notice her apology or the fact that his back was now resting against the cold, hard surface of the lab floor. Liking their new position, very much in fact, Sherlock pulled Molly's face back up to his and ran his other hand underneath the lab coat pinned between them.

The cold tips of Sherlock's fingers against her skin caused Molly to jump. She gripped his shoulders quickly, to stable herself, and hooked her left leg over his torso. A sly smile graced Molly's pink cheeks and she began rocking into him.

"Molly, Molly," Sherlock panted, searching her eyes questioningly.

Her smile perked up to the right and she raised both brows in reply. He pulled her face down to meet his once more, closing his eyes briefly, before opening them again to confirm it was really her, laying on top of him in the lab at Barts.

"Would you like me to move off?" Molly asked confused at his sudden stillness.

Sherlock let out a low laugh. "No, no. I think I quite enjoy this." Sherlock's eye flitted to the side and back to hers.

"You sure? You seem a bit uncomfortable…"

Sherlock rolled his eyes. "Not about you," he uttered as a side thought. He leaned in close to Molly's ear and whispered slowly. "It's back."

Her eyes followed his line of sight this time and landed on the fly sitting a foot away, rubbing it's front legs.

"Bloody hell!" An intern just outside the lab jumped at a sudden shriek from within.

He approached the doors to the lab cautiously. From behind the window he noticed a petite brunette with ruffled hair jump up from the floor and grab a canister before ducking down again.

The intern shook his head in confusion and started to walk away. Seconds later he was running and the fire alarm was going off.