From blushing brides turned cold-blooded killers to smitten grooms with shocking dark sides, "Fatal Vows" examines the criminal psychology behind deadly divorces. Guiding viewers through actual stories of love gone wrong are psychotherapist Stacy Kaiser and forensic/clinical psychologist Dr. Brian Russell, who examine each couple to better understand how the marriage turned from flawed to fatal. Stylized re-enactments are supported by interviews with family, friends, law enforcement, and potential victims of the crime, while Kaiser and Dr. Russell provide analysis on unions that break down until divorce and murder collide.