Koulsy Lamko recreates the horrors of the Rwandan War (1990-1994) through the memory of a queen, raped by a priest and murdered by his followers, who reincarnates in the body of a falena (night moth). The gaze of the butterfly reveals the postgenerated world and a collective memory that is debated before an extremely brutal and painful chapter, as well as the individual attempts to make hope reborn.

The novel allegorically describes the genocide of the Tutsis, borrowing a resource from the griots or narrators of the region, and is woven by several subplots, ranging from the crossing of a young woman to seek the tomb of his aunt, to historical evocations Which survivors hold when talking in cafes.

The song of the hills is one of the best works produced on this episode in the framework of the project: "Rwanda write by duty of memory".