Ninety years after the First World War, police in a Victorian country town uncovered inside a velvet-lined display cabinet, the mummified head of a Turkish soldier - a bullet-ridden souvenir brought home from Gallipoli by a returning Anzac. The macabre discovery launched Jeff Sparrow on a quest to understand the nature of deadly violence. How did ordinary people - whether in today's wars or in 1915 - learn to take a human life? Was it hard to kill another person or was it terrifyingly easy? And what happened afterwards? What did war do to soldiers to make hoarding a human head seem normal, even necessary? The questions lead Sparrow on a journey through history and across the US, talking to veterans and slaughtermen, executioners and academics about one of the last remaining taboos. Compassionate, engaged and political, Killing takes us up close to the ways society kills today, in a prolonged meditation on what violence means, not just for perpetrators but for all of us.