Oliver Sacks meets Stephen King"* in this propulsive, haunting journey into the life of the most studied human research subject of all time, the amnesic known as Patient H.M., a man who forever altered our understanding of how memory works--and whose treatment raises deeply unsettling questions about the human cost of scientific progress. For readers of The Immortal Life of Henrietta Lacks comes a story that has much to teach us about our relentless pursuit of knowledge. * Kirkus Reviews (starred review) In 1953, a twenty-seven-year-old factory worker named Henry Molaison--who suffered from severe epilepsy--received a radical new version of the then-common lobotomy, targeting the most mysterious structures in the brain. The operation failed to eliminate Henry's seizures, but it did have an unintended effect: Henry was left profoundly amnesic, unable to create long-term memories. Over the next sixty years, Patient H.M., as Henry was known, became the most studied individual in the history of neuroscience, a human guinea pig who would teach us much of what we know about memory today. Patient H.M. is, at times, a deeply personal journey. Dittrich's grandfather was the brilliant, morally complex surgeon who operated on Molaison--and thousands of other patients. The author's investigation into the dark roots of modern memory science ultimately forces him to confront unsettling secrets in his own family history, and to reveal the tragedy that fueled his grandfather's relentless ex