"Worlds Apart: The Mafia Daughter" follows a young woman named Tennly O'Brien, who returns home after three years away, only to find that everything in her life has changed. She is no longer close to her father, whom she blames for the reasons behind her absence. She discovers that her family leads the Irish Mafia in the United States, and now she must learn to navigate the male-dominated world of organized crime as she learns she is to become the first female Irish Mafia Boss. As she confronts these challenges, she also attempts to resolve her relationship with her childhood best friend, Conner Marks, who has developed a bad boy persona that her father despises.

Tennly possesses a darker side that she knows how to harness when necessary, especially when she feels threatened or needs to protect her family. As she learns more about herself, she faces more questions and challenges, both emotionally and physically. Is she just a regular teenager, or is she a weapon for the mafia? Is she just friends with her childhood best friend, or is there something deeper? It's her journey through love and loss as it unveils a startling truth: the world of wealth she inhabits and the world of the troubled boy she loves are not as far apart as it seems, igniting her transformation from weapon to first female boss.