Samantha Burke, 15 year old american, visits her grandparents in london for the summer. While there she discovers they live next to singer, Harry Styles. She has never seen this boy in her life... Or has she? Were the two friends as children? Why doesnt Sam remember? As Harry and Sam go through challenges to get her memory back.. the two fall madly in love.. only one problem... when the summer ends... they will be thousands of miles apart... And paparazzi following their every move... will Harry give up his carreer for her? or will she give up her normal life for him?..

Ever heard of the butterfly effect? They say that if you travel back in time and accidentally step on a simple butterfly, the whole future will change. One simple mistake can cause the end of an entire world or maybe nothing will change at all. Harry Styles didn't travel back in time, but he had made mistakes, lots of them. But there was one particular mistake that destroyed his whole world and now, one direction is over. But not all is lost, Annabelle, a diehard fan, covers their famous 'what makes you beautiful' single in response to the breaking up of the band. As always the videos views sky rocket and of course at least one member of the band is bound to see it and he does. One thing leads to another and now Anna is going to help him find his mates. But will that stupid mistake in the past cause devastation for Harry's future? The butterfly effect doesn't show mercy, it's his mistake and so, he must pay the consequences... Or will he?