"You" is a psychological thriller novel written by Caroline Kepnes. The story follows a charming and obsessive bookstore manager named Joe Goldberg who becomes infatuated with a customer named Guinevere Beck. Joe uses social media to gather information about Beck and slowly inserts himself into her life, all while justifying his actions as acts of love. As Joe's obsession with Beck grows, he becomes willing to do whatever it takes to possess her, even if it means resorting to violence. The novel explores themes of love, obsession, and the dangers of blurring the lines between fantasy and reality.