"Climbing out the back door, didn't leave a mark.

No one knows it's you, Miss Jackson."

The lights came up – the first notes purred from the bows of the strings, closely followed by a tremendous chord from the piano. In the brightest light in the centre of the stage, stood a girl in a gown of red lace, just waiting for the music to reach its peak, waiting for her cue to belt out the first notes. It had been too long since she had felt warmth like this, from the theatre lights and the perfect harmonies of the orchestra. The natural curl of her brunette hair shined in the light and brought out the red of her dress. She looked out over the audience feeling as content as one considering the situation behind the scenes – everything was starting to settle and everything was starting to go back to the way it was before. She was on stage – in the lights – and combining the two things she loved most in the most in this world. Singing, the audience ablaze with awe as she pours out the emotions she so often keeps held in and being undercover.

She opened her eyes and took a small step further into the light as the orchestra swelled to the moment before her cue, when she caught the eye of a man in the front row – and of all the people to catch sight of before she launched into her solo - of course it was him, and it was enough to send her heart racing in a panic and her head into a dizzying spin.

And there he was, as though nothing had changed – and she was back almost five years ago, with those cold and manipulative eyes staring straight into her mind and soul.

The flight to London had been boring and uneventful. Emily Jackson had spent hours flicking through various channels and movies on the in-flight entertainment but nothing had taken her fancy. She's never been big on either, but she had read the only book she had packed whilst waiting in the airport, so she had spent the rest of the flight trying to remember her way around London from the two years she had spent there before relocating to study music in New York, majoring in piano and voice, two instruments she'd pursued since her youth.

The flight landed as the sun tried desperately to brighten the city of London through the almost constant cloud cover that loomed over the Thames. She snaked her way through the airport, dragging her luggage behind her, before finding the taxi bay and clambering inside just before the rain settled into a gentle drizzle.

As the cab rolled through the streets of the city, Emily thought back on the last time she was in the city, four years ago before her spur-of-the-moment decision to study at Julliard. She had spent two years before that living with one of her only friends, Sherlock Holmes. She'd run out on Sherlock on the whim that drove her to New York and she hadn't looked back since… Well, except for that moment six weeks ago, as graduation dawned over Julliard and over Emily. Where else would she go? She loved New York and she loved every note of music she's played and sung at Julliard, but it was time to move on and she couldn't help but think of the love she had for London and the thought of seeing Sherlock again.

It wasn't like that – not one of those special friends things… They were just friends, like brother and sister and had been since her youth. There were ten years between her and Sherlock and Sherlock had been her babysitter during his teenage years. As an only child, Emily relished in the time Sherlock took in keeping her company and the young genius had taught her everything about his 'science of deduction.' After finishing high school, Emily had followed Sherlock into London and often took part in his cases for Scotland Yard, but had also worked under the hand and guidance of his brother, Mycroft Holmes. The elder Holmes brother had been somewhat absent in Emily's youth, with almost eight years between the two brothers', Mycroft was only ever around the House of Holmes during holidays or family gatherings.

But when Emily Jackson first moved to London she found herself stuck for funds and Sherlock's were wound up in a variety of illicit stimulants Rent needed to be paid, so Emily began honing the skills of deduction learnt from Sherlock, along with her youthful allure and quick wits and began working undercover for Mycroft Holmes in various situations. Regular reports on the younger Holmes were also expected and paid for generously by Holmes the Elder and Emily's relationship with both Holmes brothers extended.

In the Summer of the year she turned twenty-one, Emily Jackson woke up to another cloudy London day and decided to study in New York, without so much as a goodbye to her friends. She knew Mycroft and Sherlock better than any other person in the world and she knew that they'd find her soon enough, even if they didn't make their presence known. It wasn't long after she arrived in New York that she received an acceptance letter from Julliard and another confirming that her study had been completely paid for, signaling that Mycroft had indeed found her and was insisting that running off to New York was okay, at least for him. But knowing Sherlock, Emily knew that she wouldn't be getting away with abandoning him in the middle of case, early in the morning without a goodbye.

Emily's suspicions were confirmed when she walked up the stairs of the 221B Baker Street to knock on the door of the flat up the stairs, have it answered by Sherlock's curly mop of dark hair and have it disappear as he registered the guest and slammed the door shut in her face.

It was the usual cloudy London day – nothing unusual, which grinded the gears of the only resident of 221B Baker Street, Sherlock Holmes.

Sherlock Holmes was perched on the sofa his hands clasped together and resting on his chin. He was dressed in nothing but his second-best dressing gown – there was no need to be dressed today if he didn't have a case to work on. It would just be a blur of violin music, chain smoking and pacing around the flat and the previous three days had been just the same. Sherlock was certainly on edge – it had been three years and six months since he had last touched any remotely illegal stimulant, heroin being his most regular choice, but he had sworn to his mother that he'd stop, after two trips to the hospital in the six months before. He had stuck to his word, knowing that the consequences, mainly socially, would only be more painful on his part.

So Sherlock was forced back into simply smoking when the cases diminished, which took the edge off for the first few days, but after three days of the same thing, Sherlock was starting to become extremely irritated. Mrs. Hudson had the pleasure of bearing the brunt of a tantrum earlier in the morning, which Sherlock would pay for guiltily later, most likely during the high of a new case.

He was in the middle of pacing, violin in hand, across the patch of carpet between the linoleum of the kitchen floor and the back of the spare armchair, when there was a knock at the door. Tentative, thought Sherlock, immediately ceasing his pacing. Nervous, could be Mrs. Hudson after the incident this morning. It must be her, no one else, John has a key and I saw him take it this morning. Plus his knocks are never that delicate. Must be important, she'd usually leave me alone when I'm like this until I have another case unless it's a problem. Should answer the door.

Sherlock placed his violin back in its usual stance against his leather armchair before crossing to answer the door, very much so expecting a reluctant Mrs. Hudson with news of a case or something from Mycroft, but the face he saw as he opened the door brought waves of something unexpected to his core – an artful, wavy mess of chocolate-coloured hair falling over the unmistakable eyes of the person who had once been closest to him, who had been his prodigy of deduction – she was the one person who kept him in check, who respected everything he was, who he had watched flourish and grow despite the negativity surrounding her childhood. He scanned her, top to bottom – noticing all the tiny changes and every other thing that hadn't changed at all – her hair was obviously longer, but her eyes were still the most beautiful and complex dark brown, with a startling mix of gold and black closer to her pupils. She had obviously had a long flight, and this, 221B Baker Street, Sherlock, had been her first stop after departing, taking in the luggage resting by her side. She looked the same, minus the sleep deprivation and the length of her hair – she looked like the Emily he remembered – the Emily who had… run out on him without a word in the middle of one of the biggest cases Sherlock had ever experienced and settled in New York City without any hint of contact.

And with that thought, Sherlock swiftly shut the door in the girl's face and returned to the sofa, head in hands and mind racing with the things that Sherlock had sworn from a young and vulnerable age to ignore – feelings.

Emily Jackson stood on the internal landing outside of Sherlock's flat in London, not as stunned by the slamming of the door as one usually would be. She had expected something of the sorts, whether it was yelling or utter ignorance on Sherlock's half, but there was a small part of her, the part that had missed Sherlock for the entire four years, that had hoped he would be calm and welcoming when she turned up on his doorstep. Now that part of her was upset and it was hard suppress that part of her now that she was back in London, and so close to both Sherlock and Mycroft.

"Ooh, that wasn't so good, dear, was it?" The soothing voice of Mrs. Hudson floated up the stairs as Emily sighed, regaining her composure and turning to walk back downstairs, towards the spying landlady, who had let her into the building only moments before the dramatics of Sherlock Holmes. As she approached the bottom of the stairs, Mrs. Hudson continued, "Would you like to come into mine for some tea, dearest?"

Before Emily could respond, there was a knock at the front door, which Mrs. Hudson rushed to answer.

"Car for Miss Jackson?" a rather rehearsed and stoic voice asked as soon as the door opened, and Mrs. Hudson turned to see Emily already making her way out of 221B and back onto the street. After a quick departing note to Mrs. Hudson, the man who belonged to the voice took her bags, placing them in the boot of a sleek, black Jaguar, which Emily then climbed into the back seat of.

Fastening her seatbelt, Emily turned to face the expected figure in the seat beside her – in all the three-piece-suited glory of the British nation, sat Mycroft Holmes, his hands fastened patiently in his lap, and umbrella hooked over his knee.

"Well, Miss Jackson," the silvery voice of Mycroft made her shiver after four years of absence, "Welcome back to London."