My Firefighter Ex-Husband Burns in Regret tells a story that following the tragic death of their daughter Alyssa in a youth center collapse, Hazel seeks justice and revenge on her firefighter husband Jace, who chose to save his ex-lover Candace and her daughter, Kimberly, instead. Consumed by grief and rage, Hazel holds Jace and Candace responsible for Alyssa's death. As she navigates her sorrow, Hazel transforms her pain into a drive for charity, establishing a foundation to help children. Burdened by guilt, Jace tries to make amends for his decisions, leading to his self-imposed exile. Ultimately, Hazel moves on, finds new love, and leaves Jace to face the consequences of his actions.