In this episode of HHH, we dive into the chilling true story of William Palmer, the Victorian doctor infamously known as “The Prince of Poisoners.” Born into respectability, Palmer built a double life fueled by gambling addiction, mounting debt, and calculated betrayal. We explore his troubled upbringing, reckless young adulthood, suspicious family deaths — including his wife Ann, his brother Walter, and multiple children — and the infamous poisoning of his close friend John Parsons Cook. From manipulated evidence and destroyed poison bottles to one of the most sensational murder trials in British history, this episode uncovers how Palmer used medicine as a weapon, how he nearly escaped justice, and why his case forever changed forensic toxicology and criminal investigations.