Wealthy heiress Emily married into the Blackwood family three years ago. Now her weight has ballooned to 350 pounds and her health is failing fast. She notices a strange pattern—she slims down whenever she leaves her in-laws' house, only to swell back up the moment she returns. Suspicious, she plants a hidden camera and uncovers the conspiracy: her mother-in-law, Dorothy, has long been mixing pig-fattening additives into her meals, and her husband, Marcus, knows and plays along. Together they covet her pre-marital assets and have taken out a hefty life insurance policy on her, hoping she dies of obesity-related complications—while Marcus carries on an affair with Sophie on the side.
Emily gathers evidence, and with the help of her best friend, her lawyer, and the police, she foils their plots to forge documents, force her into a hospital, and torch the evidence. At trial, every crime is laid bare, and Marcus and Dorothy are sent to prison. In the end, Emily reclaims her fortune, recovers through treatment, steps out of the trauma—and begins a new life.
