an expert assassin the queens guard dog the Serpent was known for being the best assassin in all of london . No one knows there real identity or gender . very few have ever gotten to look at there face . what if one day Ciel Phantomhive bumps into them while they are on a mission . what if they get intrigued by him and his demon butler. what if they has eyes of a snake that can see inhuman things . what if Ciel and his butler think they are a he while the truth is its a she pretending to be a he .now who is this serpent assassin , its no more than Y/N L/N . i hope you guys like the new story .