Locard's Principle of Exchange
"Wherever he steps, whatever he touches, whatever he leaves, even unconsciously, will serve as a silent witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes, the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or collects. All of these and more, bear mute witness against him. This is evidence that does not forget. It is not confused by the excitement of the moment. It is not absent because human witnesses are. It is factual evidence. Physical evidence cannot be wrong, it cannot perjure itself, it cannot be wholly absent. Only human failure to find it, study and understand it, can diminish its value." – Edmond Locard
Mycroft
"Caring is not an advantage, Sherlock." The young man said to his teen-aged younger brother. "After all, Redbeard was old and sick." It is something Mycroft learned before he was Sherlock's age when their oldest brother died. Sherlock was too young to remember Ford with any clarity but Mycroft did.
As Mycroft watched his older brother slowly weakened by the cancer that ravaged Sherrinford's body, Mycroft hardened his heart. By the time the funeral happened for the eighteen year old brother he idolized eleven-year-old Mycroft Homes had no tears left. He realized he would have to teach his baby brother, three-year-old William that it didn't matter if you cared, they still went away.
Lestrade
Twenty-three. Long, dark, curly hair that hung in greasy ringlets framing an aristocratic face. This wasn't the first time that DS Gregory Lestrade dealt with this young man and he hoped it wouldn't be the last, although he hoped for different circumstances. Sherlock Holmes was one of the most churlish junkies he had ever met. Behind the constricted pupils was still a quick intelligence and eidetic memory. Still, there were the drugs.
A few phone calls and an out-patient treatment scheme later, Sherlock Holmes sat opposite DS Lestrade's desk reading cold case files. Three cold cases in an hour then they struck a deal. Sherlock wouldn't get high again and Lestrade would allow him to help New Scotland Yard on occasion.
Mrs. Hudson
Seventeen steps to the flat, a look around and she had a new tenant in 221B Baker Street. A long-time acquaintance of his mother, Martha Hudson got herself caught in the whirlwind that was her husband's drug cartel. She did know everything about it and often assessed the quality of the marijuana that passed through. Sherlock knew it but that didn't stop him from pushing it all on Frank Hudson, after all, she didn't pull the trigger that fateful night. She was actually in Sussex visiting Violet Holmes and the family she had left in England.
Still it was a relief. Frank was a violent man and frequently took the frustration of a bad deal out on Martha. He was careful not to hit her face, but he would hit her none the less. A plane ticket to Florida, a meeting with Miami-Dade law enforcement, and a flight back to Heathrow later Francis Hudson was sentenced to death for the murder of an "associate". Mrs. Hudson invested the money she had hidden away (she was a brilliant accountant after all) in London real estate and never really had to work again.
Molly Hooper
Molly Hooper, Specialist Registrar, dried her hands and made her preparations to go home. It had been a long day and thoughts always went to home when she was tired, to the two someone's that were waiting for her there. One was a sometimes grumpy and moody man-child that she loved with all her might. The other was their toddler son. She unconsciously allowed her hand to settle on her belly where their second was safely nestled and growing.
The first time she met Sherlock Holmes, she was taken with his looks. It took a long time, at least six months, to be taken with him but she learned to see through all the words meant to push away and hurt. They slowly grew close and even closer after his return from the fall. A night in a cold, damp warehouse plotting how to tackle the problem of Moriarty once and for all lead to not only the final fall of an evil criminal but marriage and family.
John Watson
Doctor John Watson, late of the Fifth Northumberland Fusiliers was wondering what he got himself into. First of all, what kind of a name was Sherlock? He was very condescending, moody, demanding and childish. Still needs must; John needed an affordable roof and 221B Baker had one.
The men became fast friends, not lovers like the rumours said. They served as each other's best man and were godfathers to each other's firstborns. Sherlock helped to repair John and Mary's marriage in those strained early days. They read each other well and worked famously together. A chance meeting of an old friend, a coincidence of both needing someone (in more ways than just a roommate) changed them both in ways neither would ever completely comprehend.
"Every contact leaves a trace."
