IT all began with a dreadful and powerful experience of death. In 2004, when Aceh was devastated by a tsunami, B.W. Purba Negara, who was an environmental activist, became a logistics volunteer for the disaster relief effort. There were thousands of dead victims, and Purba helped recover hundreds of bodies.

"Maybe 200-300 bodies were taken by trucks to mass graves every day. None of them were identified," Purba told Tempo. It was at these mass grave