Author's Note:

Starting a Sherlock fanfic. Scared because of the complexity behind the characters and hoping my original character can match up!

I do not own Sherlock.

Enjoy!


1.

Paris is a beautiful city. No matter how cliché it was, Olivia Tate couldn't help but think: Paris was even more beautiful at night. It was the City of Lights, not so much the city of romance, in her not so humble opinion. Well, it could be. She just hadn't seen any romance, but it was probably because she didn't care enough to look. Stranger romance, it was weird-it was practically alien to Olivia. Sure she had been in her share of romances, but they never involved that much PDA or touching in general.

But she was only twenty six, she still had a while to experience touching from the opposite sex.

No, what Olivia Tate was doing in Paris was more than sight-seeing and people stalking. She was here on a...vacation as only she would call it. Olivia smirked as she thought of her 'hunting ground'. The great country of England. Home of so many lovely places to go, things to see, people to...well people can be used for all kinds of things. And so can museums. But she had overstepped many boundaries back in the great land of England, which was why she was towards the end of her two year hiatus in Paris. Getting away from the busybodies of the English government and police force. Really, they both were quite bothersome.

She didn't have to stay in England. But it was quaint. She was nomadic but for some reason she always came back to England. After China, after Singapore, after America. Always England.

...Two Years Ago...

Olivia Tate walked into a building, a very fancy building with old architectural designs, yet a very modern and high tech on the inside. Ah the government, Olivia thought with a smirk, they thought they were so clever trying with their underlying metaphors of the combination of the old culture and the new.

Agents and government officials stared at her as she passed. She rolled back her shoulders and kept her proud smirk fixated on her face, her mask of cool, calm composure. Not a hard mask to keep on. Not a facade just an exaggeration of the truth. With each step she took, the click of her heels on the smooth marble floor sounded throughout the building mixing with the sounds of softer, less confident footsteps and typing and whispered mutterings from the lackeys of the government.

She stopped in front of a man, a man exuding power. A man of power and he knew it. Foolish man. If he had so much power, how come he couldn't stop her?

"Miss Alexandria Langlis," the man of power greeted.

"You called, but I am Teresa Montgomery, I know no one by the name of Langlis," Olivia said, barely keeping the smugness out of her Scottish brogue. Congratulations to the British government, they had made it farther than the other governments. Good for them, too bad they wouldn't get farther than her Langlis front.

"Enough games, Miss Langlis," the man snapped, "We know of your true identity now, Teresa was just a ploy.

"Yes, very good," Olivia smirked, "Now why am I called here?"

"We have reason to believe that you are in association with a notorious thief that goes by the name of the Mistress," the man said, "Is this true?"

"Do you have anything to prove of this so called association?" Olivia asked.

"No-," the man started.

"Then why are you wasting my time?" Olivia asked, "I am not in association with this burglar. Burglary is below me, do you know how much my family makes a year? Why would I need to associate myself with those kind of people?"

Foolish man. He thinks he understands what he is trying to solve.

"Well," the man said flustered, "do you have any idea of the whereabouts of the Jade Sphere?"

The Jade Sphere was a pricy jewel that only the queen and one other 'mystery' person in the government know about its whereabouts. This Sphere was among the top ten most valuable gems in the world.

"The Jade Sphere?" Olivia asked slowly, "I'm afraid not, however, I have read it has been stolen."

"Yes, we are getting closer and closer to the thief," the man said, "Our ties led up to the Langlis family, there was a lot of financial activity between the Mistress' thievery and the family. We went through their banking records and found the offshore account."

"What are you telling me this?" Olivia asked.

"Well your family is very powerful, Miss Langlis, we believe that the criminal in question will try to sell the jewel to the highest bidder, to get rid of it," the man said.

"But then wouldn't they need to give it back to the government," Olivia said with an eye roll, "Who would buy the jewel? You obviously know nothing about jewel thievery. They cannot sell a highly profiled piece, jewelry or art. In this case, the thief will most likely cut the jewel down and sell the jade bits to local stores or makers or just buyers in general. If you're going to call me here, at least get a decent understanding of what you are accusing me of."

The man just stared at her. Olivia fought the urge the chuckle deviously. The Langlis family was such a good cover story. They owed her a favor, so she posed as Alexandria, the daughter no one knew about. The real Alexandria was dead, but now Olivia had her information, her security codes and her life in her hand. It was only her second name, she kept her first defenses strong as well as her last. Masquerading as Alexandria Langlis was simple and extremely believable. The Langlis family was notoriously secretive. Even the government couldn't crack them because the government placed their trust too heavily on some people. And the Langlis's had money. Lots of it. And in the past they had made large, helpful donations to the government in times of crisis. The British government couldn't touch them.

"By the way, how did you discover that Teresa Montgomery was truly Alexandria Langlis?" Olivia asked. She always loved it when the government gave away secrets to those who were 'trusted' it gave her a chance to strengthen her ties and other identities.

She had grown sloppy and now her first identity was discovered. She had been living as Teresa Montgomery since she was one. Olivia Tate had been homeschooled all her life, her parents had died when she was one and a woman had found her, naming her Teresa Montgomery. She had discovered her true identity of Olivia Tate, but for all everyone knew, Olivia Tate never existed.

She used these identities, her numerous connections and her overall ability to keep a secret to prevent the government from ever having the hope of touching her. Or discovering her solo operation. It was also a statement. She didn't need the different identities. But it was fun making the government seem foolish and unknowing. It was all a game to her. A fun game that no one had the hope of winning. They would always lose and she would always win. And Olivia Tate loved to win.

"It was simple, Teresa Montgomery had made two visits to the Langlis manor of recent and once we traced their money deposits to a small Swedish bank on the coast of the country which were being taken out by a Teresa Montgomery," the man said.

Olivia raised an eyebrow. Not bad for the government, no bad at all. It must have taken them years to figure out the small Swedish bank the Langlis' were depositing money to. The Langlis' started owing her when she turned twenty, six years ago, but she had started her operations when she was eighteen and she was extremely active since then.

Eight years of extremely active and obvious action. Honestly, she had been leaving her signature at every operative she worked in. No hints, just a signature-a simple piece of white paper with the Mistress signed in loopy cursive, so different than her own angular font. It was obvious that she had been circling the country, the world, but had never been apprehended. The government was bound to discover the back door of her first identity. But they'd never connect her to the Mistress. There was no evidence, just a tie to the Langlis family.

It was lucky that the lady who found the one year old Olivia Tate was an old village woman in a small farm in Scotland, never told anyone about finding Olivia and the knowledge that Olivia was not truly the daughter of a village woman died when woman died.

"Well, you know my family," Olivia said with a fake smile, "They're full of secrets."

"Secrets the government would like to know, for the safety of the people living in it," the man said.

"Well, would you look at the time," Olivia said straightening her already straight black pencil skirt before smoothing her straight black hair, "I must be going. It was lovely meeting you...?"

"Mycroft," the man said taking her hand, "Mycroft Holmes."

...Back in the Present...

Olivia found herself staring at the Mona Lisa in the Louvre. She stared at that mysterious painting in that climate controlled environment, encased in bulletproof glass. She stared into the unblinking eyes of the woman and the coy smirk of Mona Lisa. What was her story? What hid behind those eyes and that self assured little smile, or smirk as it appeared to Olivia whenever she visited the museum.

Olivia came to the museum many times. She was somewhat of an expert on art museums and art in general. She had an Art History major that was hidden behind a more prominent Mathematics major.

She had so many layers. She felt so similar to the Mona Lisa. So many mysteries that no one could figure out, but everyone tried. Yet no one had came close. So protected, yet she managed to get stolen and vandalized once or twice but otherwise it was unheard of.

She remembered when the society of underground thieves in Britain held a competition to steal the painting. Olivia

smirked. She had the painting in twenty four hours after the competition started leaving a piece of paper reading 'the Mistress' in the place of the painting and had kept it for twenty four hours. She was nineteen and she had only been working for one years. Her experience had worked to her advantage, she didn't over think the situation. Olivia watched the detective investigating her heist. He had been so dedicated but so annoying. She had planted the painting in his apartment building in Paris with her signature. That became her touch.

That heist had made the Mistress known. And her reputation became known amongst all the thieves in the world, all the governments and the people who had read about the heists the government kept under wraps. She had stolen hundreds of paintings from numerous museums, as well as a valuable jewel or statue here and there.

Her eyes flittered from the painting to the security guard that was staring at her intently. Probably waiting for her to whip out a camera and take some illegal photos. She stared back at him and raised her chin up daring him to question her. Olivia ran a hand down her, now natural caramel colored curls as she sauntered out of the museum.

She heard footsteps behind her and she ignored it, waiting for the person tailing her to follow. She could hide, she was pretty good at hiding, but why bother?

"Hey, you," a gruff male voice said.

Olivia stopped and turned around, "I have a name." And she was curious to know which one was going to be used.

"I've been informed that you are Miss Alexandria Langlis," the man said, "The British government sent me here to find you. You are not an easy woman to find, Miss."

"That's the purpose," Olivia answered, "Now what does the government want from me."

The man stood in front of her two paces exactly and pulled out a gun. Olivia rushed him the moment his hand reached out of his pocket. She grabbed his hand and twisted it, crushing it beneath her rather delicate looking hands. Foolish man, was this a test? She wondered. The gun fell to the floor and Olivia picked it up.

"Does the government want me dead?" Olivia asked, "Well, this is a first."

"No," the security guard said standing up from where he fell and massaging his hand. It wasn't broken, Olivia wasn't strong enough to break it, but it would be sore and bruised for a while. "It was just protocol. I was supposed to hold the gun up and ask for identification."

"You could have done that without the gun," Olivia said now pointing it at him. She reached into her small purse with a free hand. The guard stared at her picture.

The guard nodded, or rather he probably wasn't a guard, more likely a government agent.

"Well, I guess my vacation is over," Olivia muttered.

...

Olivia was told by that Mycroft Holmes bloke that she met with two years ago some extremely interesting information. He met her with a private governmental plane going back to England.

He showed her, via her tablet, the body of a man, completely white, but no discernable wound marks. Olivia figured that it was from some kind of needle mark, or poison being injected into his body. Lo and behold it was a needle of air being pushed into an important nerve in the neck doing some kind of medical mumbo jumbo. She zoned out when he started going medical examiner on her. She didn't understand that aspect of crime.

"His body had been labeled with a piece of paper labeled 'the Master'," he said, "Now the Mistress had been missing in action in England for a while. Right after we had you suspected. Are you sure you are not in association with her?"

"Can you prove any association yet?" Olivia asked.

"No," Mycroft had said begrudgingly. Olivia could tell he didn't like saying no and he liked to have complete control over the situation.

"Then why am I here?" Olivia asked.

"Because all our leads of the Mistress go every which way," Mycroft said.

"Do you still suspect me?" Olivia had asked again.

"No, you are no longer a suspect," Mycroft had informed her, "The government cannot find a solid link to you and the Mistress and your family made sure to keep it that way."

"Then you won't find a link," Olivia had said with a smug smirk, "No one will ever find out anything about the Mistress. The American government could not, the Chinese government could not, I don't think the British government can either."

"However," Mycroft had said with a stern look in her direction, "while the government still thinks of you as Alexandria Langlis and since you have that family so wrapped around your finger it cannot disprove it, I have digressed. I do not believe you to be the young Miss Langlis."

"Oh," Olivia said raising an eyebrow, "And what power do you have that is greater than that of the government?"

"The power of deduction," Mycroft said, "And using that power, I have deduced that you share no knowable link with the Langlis family, your features are not similar at all."

"Then who am I?" Olivia asked, "What is my true identity?"

Mycroft Holmes stared at her. The government didn't know. He didn't know.

"Then you cannot prove it, I am Alexandria Langlis," Olivia said with a shake of her head, "Your deduction has not concrete back up. It is what it is, a deduction-mere speculation, not solid proof. Circumstance not evidence. Test my DNA, it will come up as Alexandria Langlis but you've already done this, Mister Holmes, I can tell. That's proof enough."

"But it is enough to make me continue to search, I received this deduction under a trusted source," Mycroft said, "And I have searched and I have reason to believe that you are the Mistress."

"Well you cannot PROVE that," Olivia said, "This still does not explain why you brought some man to remove me from my vacation in Paris."

"Someone going by the name of the Master has been killing people, both rich and poor," Mycroft had said, "The government thinks that this Master is an acquaintance of the Mistress."

"The Mistress works alone and does not kill," Olivia said easily.

Inside her brain was working over time. How could anyone think that a murderer was working with a thief? Especially one as renowned and professional as the Mistress? Killing in thievery was the lowest of the low in that craft. The craft of thievery was sacred, it was an art of sneaking and not being caught. Murder was like cheating, like spitting upon the name of the craft itself.

"Yes, but those people that had been killed, all their belongings went with their life," Mycroft said.

"And the government thinks that is why the Mistress is working with this Master," Olivia said, "Well the government is foolish. The Mistress does not kill. Murder is below her, below all professional thieves, leaving people alive and desperate is much more fun."

Mycroft Holmes stared at her.

"You know a lot about the Mistress," Mycroft Holmes said.

"Can you keep a secret?" Olivia fake whispered, "You're right. I am the Mistress. Tell anyone and it is my word against yours. I know you hold a great position in the government, you practically are the British government, but the Langlis' will pay any amount of money to keep me safe. They will disprove you, even if it means using a scapegoat, and you will be the fool."

Mycroft Holmes looked stunned.

"You forget who pays the government," Olivia said, "The Langlis' have so much information the government keeps from its people. You tell them about my identity and I send the order to bring England to her knees. Naturally, that would be poor for you and your affairs."

Mycroft stared at her.

"Do you think I had not thought about this?" Olivia asked rhetorically, "That I would not have a back-up plan? Every country I have ever stolen from I have so much dirt on them, I have knowledge of all conspiracies and proof about all of them. There are so many secrets each of the governments are keeping from their citizens and I know the great majority of them. I could destroy each government, cause their citizens to revolt."

"Why tell me this?" Mycroft whispered.

"To let you know exactly who you are dealing with and to find your priorities," Olivia said softly, smugly, "You are powerful but so am I. But the difference is my theories have proof, yours do not. So I'm telling you my identity, knowing that you would not turn me in after finding out who I'm capable. You are the heart of the government but I hold that heart in MY hands. You control the happenings of the government but right now I control YOU."

Mycroft sat back in shock.

"I know Mister Holmes that sending me into some odd years of prison is not worth destroying a government that you are so involved in and took years and years to establish," Olivia said leaning close to the shell shocked man.

"How do I know you're not bluffing," Mycroft Holmes countered leaning close to her in return.

"Mister Holmes, I don't think you want me to prove it," Olivia whispered fixing her eyes on the man sitting in front of her.

It was silent in the plane minus the muffled roar of the engine before Olivia broke out of their staring contest to recline back on her plane's seat with a smug look and crossed arms.

"And I do not associate myself with murderers," Olivia continued, "I want to do something to find this Master. He is soiling my reputation."