Blaine Lawson is a serial dater. She has a rule where she can't stick with a guy for more than three months, and it's a rule she follows religiously because she's afraid to let anyone in. But what happens when she meets Harry Styles, the sweet guy who is determined to get her to open up about her secretive life and her dark past? Blaine may seem tough and in control on the outside, but inside she's a mess... However, Harry is willing to do what no other guy has ever done before- He's willing to fight for her, even when she pushes him away again and again.