The bigining of the end. (Prologue)

I don't own any of the Sherlock character all rights go to BBC. Her name was Sandra she was a twenty year old girl that needed to escape the clutches of her life as a sniper for her brother the famous Jim Moriarty. There were only three men in the whole world that could do it John Watson and Sherlock and Mycroft Holmes. Would she she break the chains or would she face the truth that evil ran in the family.