Who Owns My Heart (Louis)

Louis's life was going perfect until one of the most tragic events happen all of a sudden and completely breaks him. He becomes someone entirely different and even with the help of his 4 best friends he can't get over it. He goes out to party and drink all the time and it becames his usual just to alleviate the pain but its no use. Then one day someone new is introduced into his life that he can't seem to let go. She is best friends with Zayn's girlfriend who invites her to stay with them throughout the summer with no plans of a new love but anything can happen during summer. Will she leave when things get hard to deal with or stay and be there for Louis in his time of need? Is she finally the one who breaks down Louis and fixes him for the better? Or makes it all worse...