Sergio Vieira de Mello – peacemaker, troubleshooter and charismatic negotiator – lived an extraordinary life at the centre of some of the most dramatic international crises of the last half century. As UN High Commissioner he tried to bring an end to the slaughter in Bosnia, talk to genocidal warriors in Congo and clear up the fallout of the Iraq invasion, where he was killed in 2003. Through the prism of this extraordinary life, Samantha Power, one of the most prominent thinkers in international affairs today, tells the story of the flashpoints in our recent history – and the perilous world we live in.