L'extraordinaire recherche du docteur Cartault: The film recounts the incredible research conducted by François Cartault, a pediatrician and geneticist on the island of Réunion. Conducted like a police investigation over more than 20 years, his research, both medical and historical, takes us on a journey through the disease of moon children, deprived of sunlight, and on the trail of slavery in Africa. The film shows how genetics is also an astonishing trace of history.