Disclaimer: I don't own Sherlock (or Firefly).
Can't Stop the Signal
Sergeant Sally Donovan had a secret. No, nothing like that. It wasn't anything really terrible, just something she didn't like to have spread around as general knowledge. She has an image to protect, after all: a tough, no-nonsense police officer who could kick anyone's arse despite being a woman, and will always look totally hot doing so because she's a woman. Even in school, she strived to be the model of excellence. It wouldn't really seem right for people to know that she's a serious sci-fi geek.
Sure, it's become stylish again to discuss Doctor Who with her friends and colleagues now that it's back on the air, but very few people know that she's knitted her very own Tom Baker scarf which she may or may not tend to wear when she's in the mood to pop in a dvd of the classic series. And god forbid anyone should know that David Tennant is not her favorite Doctor and that Rose annoys the hell out of her.
But her absolute obsession is with the depressingly short-lived television program Firefly, created by the almighty Joss Whedon. She knows that there must be other Browncoats all over London, but they don't generally go around wearing recognizable insignia, except for, perhaps, the occasional Jayne's hat. Unlike Doctor Who, she doesn't have anyone with whom she can talk about the show, and it gets really annoying sometimes. For instance, whenever she happens to stop by Dr. Anderson's office, her eyes immediately spot the dinosaur figurines on his desk. She has to restrain every natural instinct that she has not to pick them up and have said dinosaurs discover a fertile land, which they will decide to call 'This Land.'
One day, however, after a very difficult case was solved (by the Freak, of course), Sally found herself having to testify in the court case. Sally and Anderson were about to walk into the courtroom after having shared a cab and entered the building together. That's when she spotted the would-be detective and his flatmate walking in their direction, chatting away like people who are normal do.
"Freak," she said, making a face at Sherlock; though, by now it had lost its bite and was really only out of habit, as being around John has made him seem to act a bit more human.
"Sergeant Donovan," said Sherlock, bowing his head slightly toward her. "Anderson."
"Don't you start with me, Holmes," said Anderson.
"I have absolutely no desire to start anything with you," said Sherlock. "In fact, I am inwardly berating myself for having even acknowledged your presence."
Anderson began to open his mouth in protest, but instantly snapped it shut and turned to Sally. "How's my tie?" he asked her, adjusting it around his neck.
Sally looked down at it. It was a gaudy thing, purple with orange and yellow flowers. Frankly, Sally wouldn't be caught dead in anything even closely resembling that tie. But, instead, she gave him a smile, reached out to straighten the knot, and said, "It's very you."
"I must agree with the sergeant's assessment," said Sherlock. "A man walks down the street in that tie, people know he's not afraid of anything."
"Yes, well..." said Anderson, feeling there was some sort of disparagement behind Sherlock's statement, but wasn't positive about it. "Thanks."
Sally, for her part, just hoped her eyes weren't jumping out of their sockets. Was the Freak a Browncoat? Impossible. It was probably just a coincidence. After all, if you give typewriters to a room full of monkeys, they'll eventually write out the complete works of Shakespeare. Surely it meant nothing if a sociopath sounded like he was paraphrasing a canceled science fiction program. But... She shook her head. No. But she decided she would have to listen a bit more closely when Sherlock spoke in future so she could determine better.
About three months later, Sally had forgotten about the incident. Real life was calling in the voice of four young blond women each strangled to death over the past two weeks. Sally watched with arms folded as Sherlock examined the latest victim with DI Lestrade and John Watson standing close behind him, both hanging on to his every word like they were the Freak's own personal groupies.
"John," said Sherlock. "Care to examine the body?"
"What?" asked John. "Me?"
"Anything wrong with wanting a doctor's opinion?" he said. "Have a go."
John stepped forward and knelt down to take a closer look, transforming into doctor mode. "Asphyxiation, obviously," he began. "Bruises along the neck indicate the killer used his hands. But then there's also a large cut in the back of her head, indicating she put up a fight. He probably was too strong for her and managed to tie a rope around her wrists, causing some burns there. You're probably looking for a big guy who works out."
"Very good, John," said Sherlock.
"Right, so-" Lestrade began, but was quickly cut off.
"But you're wrong," said Sherlock. "The killer was obviously a woman."
"And why do you say that?" asked Lestrade.
"Come on," said Sherlock. "Isn't it obvious?"
Sherlock rolled his eyes, as though he didn't love being the center of attention. "The cut on her head indicates the killer must have surprised her from behind, meaning they needed to rely on gaining the upper hand without just the use of their strength. The ropes around the wrist were used for the same reason; obviously the victim could have easily overpowered the aggressor if not for being bound. You can also smell a faint scent of lavender perfume."
"What about the perfume?" asked Lestrade. "The smell is on the exterior of her coat only; none on the rest of her clothes or skin. The scent must have rubbed off the killer's clothes and onto the victim's when she was being strangled."
"Okay," said Lestrade. "So we're looking for a woman with anger issues, then?"
"I'm sure of it," said Sherlock. He flashed Lestrade a smooth grin and spun around, coat twirling dramatically like he was some kind of superhero.
"Freak," said Sally, as he and John began to pass her.
"Sergeant," said Sherlock.
"You've done your bit," she said. "Now I'll be doing mine."
"I'm sure you'll be able to provide lots of useful incite into the mind of this killer," he said. "Good luck."
"Sometimes I just want to duct tape your mouth and dump you in a cell for a month," she responded.
Sherlock paused mid-stride, and swiftly turned around again to face her with a very curious expression on his face. He then walked up right next to her, invading her personal space. He leaned down so that his mouth was by her ear, and Sally could feel his breath as he spoke to her in a deep whisper, saying, "Also? I can kill you with my brain." He immediately stepped back, and Sally watched him disappear with John down the street. Under different circumstances, she would have shivered in horror, but currently, all she could do was smile faintly towards his receding figure.