At a Catholic mission in Yambuku, an oasis of peace and efficiency in northern Congo's vast jungle forests, Mabalo Lokela, a teacher, receives an anti-malarial shot for a raging fever and headache. Sister Lucie, a Flemish nursing sister, swishes out a syringe with a weak disinfectant. The next patients are injected with the same syringe and the sick man's virus spreads.Lokela was the first Congolese victim of a new African hemorrhagic disease that became known as Ebola fever. When Sister Lucie dies a few days later, panic erupts and hospitalized patients flee into the forest. With the convent connected to the outside world by a single primitive radio, the mission nuns can only pray and wonder if anyone will act on their cries for help.