The protagonist Pureza and her son Abel live in the hinterland of the Maranhão state in northeastern Brazil and work as brick makers
In pursuit of a better life, the young man leaves to work on a mine in the Amazônia. Not hearing from her son for months, Pureza decides to go in search of him. On her way she finds farms with a hidden system of slave labor and imprisoned villagers. The film is based on a true story of Pureza Lopes Loyola, who motivated the authorities to create the Grupo Especial de Fiscalização Móvel, the first anti-slavery unit in Brazilian history.