On July 22, 2011, Anders Behring Breivik detonated a bomb outside the Norwegian prime minister's office in central Oslo, killing eight people. He then proceeded to a youth camp on the wooded island of Ut?ya, where he killed sixty-nine more, most of them teenage members of the country's governing Labour Party. How did Breivik, a gifted child from an affluent neighborhood in Oslo, become Europe's most reviled terrorist? How did he accomplish an astonishing one-man murder spree? And how did a famously peaceful and prosperous country cope with the slaughter of so many of its young?.