Lucy Love, an introverted 17-year-old, and Joshua Martin, her defiant stepbrother, must navigate their complex feelings after their parents' remarriage. Initially, they clash due to their differing personalities and Joshua's disturbing past. However, they gradually develop a profound connection, which deepens into an intense, forbidden love. Faced with the potential harm to their fragile family and societal disapproval, Lucy and Joshua must decide if their love is worth the struggle. They embark on a journey of self-exploration and secret affection, dealing with high school, familial issues, and their personal dilemmas.