When colleagues at photographic equipment supplier, John Hadland's began falling ill, the locals all believed there was something harmful in the village water supply. The so called "Bovingdon Bug" took hold of many of the workers in the summer of 1971 - two men, Bob Egle and Fred Biggs died slow and painful deaths. When investigators were called in, it soon became clear that the only impurity at Hadland's was an enigmatic member of the storeroom - Graham Young. The 23-year-old trainee had been lacing the workforce's tea and coffee with a lethal poison. When detectives began digging into Young's background, they discovered a toxic past. Aged just 14 Young had been incarcerated at Broadmoor after methodically poisoning his father and sister, leaving them violently ill. The schoolboy even confessed to killing his stepmother, Molly by lacing a trifle with a deadly chemical called Thallium. The so-called Teacup Poisoner may have convinced experts that he was cured, but there was something evil brewing inside of Graham Young.