Fighting to Death, Fighting to Live

Rob, adored by the whole family because of his talent in martial arts and leadership, is kidnapped and trapped in an assassin group Shadow. After surviving the killing camp, he is selected to be the assistant of Alexander. Short, pale, but strong, Alexander, with her extraordinary sword skills, is the youngest leader of the best assassin unit in Shadow. She is the one that would train Rob into a qualified assassin, so he can help her to perform important mission. What would happen when they two come together? Why they plot to destroy the whole Group? Why they turn all they way to South? What kind of adventure is that? What's the future of Rob and Alexander?