The Assassin- Larry Stylinson

Louis Tomlinson is a trained killer. He really only does it for the money, and he has to admit he's the best on the job. So far all of his cases have been easy.
-Find the target
-Kill the target
-Get paid
-Go home
But this new case is going to be different. Louis is assigned to follow and kill a certain boy named Harry Styles.
Harry doesn't know what's coming, but neither does Louis.