In 1856, a baying crowd of over 30,000 people gathered outside Stafford prison to watch the execution of a village doctor from Staffordshire. One of the last people to be publicly hanged, the 'Rugely Poisoner', the 'Prince of Poisoners', 'The greatest villain who ever stood trial at the Old Bailey,' as Charles Dickens described him, Dr William Palmer was convicted in 1855 of murdering his best friend, but was suspected of poisoning more than a dozen other people, including his wife, children, brother and mother-in-law - cashing in on their life insurance to fund his monstrously indebted gambling habit. Highlighting Palmer's particularly gruesome penchant for strychnine, his trial made news across Europe: the most memorable in fifty years, according to the Old Bailey's presiding Lord Chief Justice. He was a new kind of murderer - respectable, middle class, personable, and consequently more terrifying - and he became Britain's most infamous figure until the arrival of Jack the Ripper. The first widely available account of one of the most notorious, yet lesser-known, mass-murderers in British history, The Poisoner takes a fresh look at Palmer's life and disputed crimes, ultimately asking 'just how evil was this man?' With previously undiscovered letters from Palmer and new forensic examination of his victims, Stephen Bates presents not only an astonishing and controversial revision of Palmer's entire story, but takes the reader into the very psyche of a killer.