On 30 January 1962, a few weeks after Tanganyika became independent, three girls at a mission boarding school in Kashasha started laughing and could not stop. Within weeks, 95 of the 159 pupils had attacks of uncontrollable laughing and crying, some lasting hours. The teachers were never affected. In March the school had to close, and the laughter spread to nearby villages. Doctors today call it mass psychogenic illness. The characters here are composites; the events are real.