Madeline Sheehan writes dark contemporary romance best known for the Undeniable series, centred on motorcycle-club culture, violence and relationships shaped by long histories of loyalty and betrayal. Undeniable follows Eva Fox and Deuce West across years as their families and club connections repeatedly pull them together and apart. Later books shift to other couples within the same social world while continuing gang conflict, friendship and family consequences. Sheehan's books are explicit, violent and strongly relationship-led, with morally difficult behaviour and long-running interpersonal conflict central rather than incidental. They fit motorcycle-club romance, dark romance and interconnected adult series for readers comfortable with abuse, crime and unstable relationships. Undeniable is the required starting point because Eva and Deuce's history establishes relationships that continue around later couples; the series is intended for adult readers comfortable with explicit sex, criminal violence and protagonists whose behaviour is often deliberately difficult. Read more Less