Rylee Devine is the little sister of One directions drummer Josh Devine. After an accident resulting in a loss of her parents, she is taken in by her brother and the band. As the spend the summer together, one of the boys finds himself falling for her, but will he break the 'Sister Rule' even if it means risking a friendship?

When Liams sister, Haley, despises Harry with EVERYTHING she can, does she fall in love with him? How will Liam react? What if niall finally finds his princess? Will Zayn and Harry split? When Haley gets pulled into the middle of everything, she won't know what to do!