For thousands of years the human heart remained the deepest of mysteries; both home to the soul and an organ too complex to touch, let alone operate on. Then, in the late 19th century, medics began going where no one had dared go before. Morris gives us a view over the surgeon’s shoulder, showing us the heart’s inner workings and failings. He describes both a human story and a history of risk-taking that has ultimately saved countless lives. Chaired by Rosie Boycott.