The astonishing true story of how Catherine the Great joined forces with a Quaker doctor from Essex to spearhead one of the first global public health campaigns. A killer virus...an all-powerful Empress...an encounter cloaked in secrecy...the astonishing true story. No disease sparked as much dread in the eighteenth century as smallpox. The virus killed millions across the globe, carrying off one in every five victims and disfiguring survivors with tell-tale pitted scars. But one mysterious method offered hope: inoculation, the practice of piercing the skin to insert a drop of infected matter and induce a mild case of smallpox. Those inoculated safely were protected from the 'Speckled Monster' and stayed immune for life. Only one problem remained: convincing people to accept the treatment. Arguments raged in Europe over its risks and benefits, and public resistance ran high. In Russia, Catherine the Great took a momentous decision: to undergo inoculation herself to set an example in her empire and beyond. In 1768, she summoned the Quaker physician and inoculator Thomas Dimsdale from his Hertfordshire surgery to her glittering court in St Petersburg to carry out the secret mission that would transform both their lives. Lucy Ward expertly unveils the extraordinary story of the English country doctor and the all-powerful Empress, whose courageous act highlighted the lifesaving power of inoculation and won praise from King George III and Voltaire. This is a fascinating history of Enlightenment ideals, female leadership and the fight to promote science over superstition.