Louis' childhood has been anything other than normal. His parents and family died in a car wreck when he was six, he isolates himself, and he lies, a lot.
Not that he means to, it's lies that have been fed to him since his Uncle took him in after the accident. The only person who hasn't cared enough to listen to them carefully is Niall, which is why Niall is Louis' only solid friend.
Then Niall introduced Harry into the picture. Louis has never felt so exposed with someone, except for his uncle (which isn't his choice) that he tries desperately to push Harry away before everything falls apart. But is it really falling apart, or is Harry finally helping Louis to piece together his childhood that had been rewritten by a monster?