The "Culpable" series, also known as the "Culpa" series, is a young adult romance trilogy by Mercedes Ron, following the tumultuous relationship between Noah and Nick. The first book, My Fault, introduces Noah, who is forced to move to Los Angeles and navigate a world of wealth and street racing, where she meets her new stepbrother, Nick, who is both dangerous and alluring. Their passionate and complicated relationship deepens in Your Fault and Our Fault, as they face new challenges and must decide if they can overcome their issues and be together.