Bitter Sweet and Strange (Larry Stylinson)
He agreed to stay so his sister could go free, but he never signed up for this.
Beauty and the Beast AU in which Harry is taken prisoner in King Louis 'The Beast' Tomlinson's castle, Master Liam Payne may or may not be a torture specialist, Master Zayn Malik may or may not be the Master of War, and no one will tell him what the hell Niall does around here.
Basically, Harry hates his enemy with a passion. Then he kind of has a passion for his enemy. Then he wonders if he and Louis are enemies at all.