How has the extremist group Boko Haram, which began as a small Islamic sect, managed to make Nigeria, the richest country in Africa, and all its neighbours, tremble with fear? Who are they and how did they become so powerful? Xavier Muntz spent a month in Northern Nigeria, in the heart of the red zone, to answer these very questions. He met with many people, all directly affected by this religious uprising. Victims, soldiers and even Jihadi sympathisers.