The story of Maddie who leaves her hometown in the United States for the sensual streets of Barcelona to seize the opportunity to do an internship for erotic filmmaker Erika Lust. At first, she is overwhelmed by her new life and her new job, the new experiences and people she's being confronted with. But soon, sparked by her dreamy roommate Michael and her new friends, the shy All-American girl experiences a sexual awakening she could have never imagined in her wildest dreams. Meanwhile, her sister Paisely is worried about her disappearance and makes it her mission to find her. Will Paisley succeed or will she be lured into the heat of a European summer? This is a tale of sexual awakenings, erotic desire, curiosity and pleasure; this is a summer of Lust..