In a narrow canoe hollowed out from a tree trunk, a teenager, Valentine Pasi, her baby son and five young brothers-in-law ended their desperate race to safety across the Ubangi river. Behind them were the murders, rapes and desolation of home. Ahead of them, profound uncertainty. For many, this deceptively placid river has become the sole safe passage from the catastrophe engulfing the Central African Republic (CAR). A fresh surge of more than 30,000 refugees has poured across the unguarded border into the Democratic Republic of the Congo – itself hardly a model of peace and stability – in the past month, according to immigration officials. They come daily in fishermen’s canoes with what few possessions they can carry and tales of intensifying horrors in their homeland. Some bear the testimony in bullet wounds. An estimated 4,000 have settled in or near the riverside village of Gbangara, one of Africa’s remotest places, nearly five hours’ drive through the jungle from Gbadolite, a frontier town where only two or three planes land each week...