A/N This is my first ever attempt at writing anything for fan fiction, criticism is definitely appreciated but please take my inexperience into account. Enjoy!

Running. She always seemed to be running where ever she went, dodging people in a busy New York street, Emma knew she had to find somewhere safe quickly. Having been to many cities around the world, New York was by far the best. It wasn't because of the great atmosphere or the spectacular variety of people you could meet, it was because for the last eight years this city had been her home. Emma had a very fulfilling job being a cop as she was able to right some of the wrong doings she had previously made in what felt like another life. Even though the past eight years seemed like it was all sunshine and rainbows, there were times when she had felt like an impostor who was going to get caught out at any moment.

Emma was running because finding another body in the center of Manhattan, which fitted the pattern of a number of murders carried out by a recent serial killer had landed her in hot water. For weeks Emma and her partner, Detective Costello have been working on a string of murders that appear to have been committed by a female assailant. As the body count increased so did the evidence, the evidence which for some reason was starting to implicate her. No one had directly pieced the parts of the puzzle together but Emma knew that the latest piece of evidence they found at the last crime scene would somehow be linked to her. She had already discovered that although she knew none of the victims, the method in which they were killed were shockingly familiar to her.

After running several blocks through the freezing rain Emma found herself in a cheap motel pacing up and down, luckily she had managed to contact an old friend at the CIA who had managed to get her on the next flight to London. Emma needed to see the one person who knew about her past but would help her regardless. The man was infuriatingly clever and didn't know the meaning of tact, but no one could argue that he wasn't brilliant. Yes, Emma was going to London and she was going to see Sherlock Holmes.