On November 13, 2015, Antoine Leiris’ wife, Hélène Muyal-Leiris, was killed by terrorists while attending a rock concert at the Bataclan Theater in Paris, in the deadliest attack on France since World War II. Three days later, Leiris wrote an open letter addressed directly to his wife’s killers, which he posted on Facebook: “For as long as he lives, this little boy will insult you with his happiness and freedom.” In his determination to honor the memory of his wife, Leiris became an international hero to everyone searching desperately for a way to deal with the horror of the Paris attacks and the grim shadow cast today by the threat of terrorism. Now he tells the full story of his grief and struggle.