A/N: Hey, so this is my first Sherlock fan-fiction, so sorry if people are out of character, feel free to give tips to help me with characterisation. So in this story Sherlock is about 32/33 and John is about two years older and it features my OC Lily who is 14 at the start of the story. It is set after 'The Reichenbach Fall' and Sherlock has been cleared and has returned, but it won't be mentioned much, apart from maybe reference to Moriarty and stuff. Anyway, I will try and update as regularly as possible, and I have loads of story ideas, and there will probably be a sequel later on. I am open to ideas and critique, but don't be too mean. Sorry for the ramble and hope you enjoy!

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Warning: Rating may go up in later chapters.

"Lil, you're completely insane!"

"Thanks Jamie, because I didn't know that already." The girl turned around and looked at the boy as she rolled her eyes.

"There.. done." She said with a sigh of relief as she finished picking the lock. She stepped back to admire her handiwork, and Jamie took the opportunity to stand back and really look at the girl stood in front of him.

She was quite tall, standing at about five foot eight. She wasn't slim, but was at an average weight. To a stranger she appeared to be about 17 but she was actually a lot younger. She had dark skin and dark brown frizzy hair pulled into a bun at the back of her head. Her eyes were dark brown, so dark in fact they appeared almost black. She had long lashes and one of her dark eyebrows was currently raised as she watched Jamie examine her. She had an oval shaped face and her dark red lips were pulled into a smile a result of the task she had just accomplished. She was wearing dark skinny jeans with knee-high grey boots that laced up to the top. She was also wearing a black hoodie with a white zip up the front that was too big for her, but she wore it anyway.

At that moment she shifted her weight to her left leg, crossed her arms and stared at him.

"Are you done staring at me Jamie? I asked you to be my look out; not assess how I look." She sighed heavily. "I'm going inside now, y'know to the building I just spent five minutes picking the lock to?"

Jamie looked up. "Yeah sorry, are you sure you want to do this?" She rolled her eyes.

"Okay, just be careful Lily, I care about you."

"Thanks Jamie, but I'll be fine" and she turned and walked into the empty building.

"What have you got for me Lestrade?" demanded the Consulting Detective as he marched into Detective Inspector's office.

"I don't even know why I let you on these cases Sherlock, you don't take it seriously enough."

"I do take things seriously, now what have you got for me?"

At that moment Doctor John Watson appeared in the office, panting after chasing Sherlock through Scotland Yard. Sherlock didn't even acknowledge him and started tapping his fingers on Lestrades' desk. Lestrade sighed and dropped the files on his desk.

"Four murders in the past two weeks."

"Four? In two weeks? That's a bit reckless isn't it?" said John who had finally managed to get his breath back.

"Details?" asked Sherlock.

"There was a women in her forties, a man in his twenties, a women in her thirties and a man in his fifties."

"Are they linked?" Sherlock queried .

"They were all killed in the same way, single cut across the throat from a simple knife."

"So we're dealing with a serial killer?" asked John.

"Which was the most recent?" Sherlock questioned.

"Two days ago, the body has already been moved to St Barts."

"Well I'll start there then, John are you coming?"

"Nah, I think I'll head back to the flat, I've got a date later and I want to look nice." John saw a hint of disappointment flicker across Sherlock's eyes, but it was gone as soon as it appeared.

"Right okay then, afternoon Lestrade." and he strolled out of the office as quickly as he had arrived. Once he had left Lestrade turned to John and sighed.

"See you later John."

"Bye Inspector."

John walked out of the Scotland Yard, hailed a cab and headed back to the flat. John stared out the window watching the streets of London whiz past. Soon enough the cab pulls up outside 221b Baker Street and John gets out and pays the fair. He walks up to the door and heads inside. There is a note on Mrs Hudson door, saying that she has gone to visit family for two weeks, and she hopes that John and Sherlock can look after themselves until then. He sighed, wondering if they would be able to cope without their 'not housekeeper' for two weeks.

He headed upstairs to his and Sherlock's flat and opened the door.

"Jesus Christ!" he shouted as he took in the scene in front of him.

There sprawled out on the sofa, was a young girl who can't have been more that sixteen years old. John's army training kicked in and he stared at the girl.

"Who are you? What are you doing here?" he demanded, still puzzled as to how she got into the flat in the first place.

She stared at him, her brow furrowing as if she was trying to figure him out.

"Sorry.." She started. "I didn't mean to startle you Doctor Watson, I haven't taken anything and don't plan on doing so. I simply wished to speak with someone, but it is clear I will have to re-think my plans.." She spoke with rather posh english accent, and John presumed she had been brought up well.

"B-uu.. h-how did you get in? Who did you want to speak to? Who are you?" John struggled to get his head round the situation. Who was this girl standing in front of him? What did she want? How did she know his name?

The girl got up and began to head for the door, but before she did she turned and looked John in the eye.

"I'm Lily, and I'm sure we'll be meeting again soon Doctor Watson. And be careful, Sherlock's new case may be a struggle, he might need my help." and with that she turned and ran through the door and down the stairs, and John could just make out her saying;

"Don't bother with your date tonight John, she's cheating on you." He heard the front door slam and he slunk down into his armchair, running the last five minutes through his head repeatedly. What just happened?

Jamie waited at the bus stop, watching as people walked by, consumed by their own little worlds. He felt a buzzing in his pocket and checked his phone.

1 new message:

Flat went as planned- I hope.

Heading back to bridge now.

-Lily x

He sighed and walked away. What are you getting yourself into Lil?

A/N: Sorry for the short chapter, but I had to set the scene. Next chapter will be longer, and definitely more interesting. Let me know what you think!

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