Katia Reiter has been directing the Guadeloupe Volcanological Observatory for about ten years. She forms a powerful partnership with Aimé, a young Guadeloupean, to whom she shares her passion for the profession. As she prepares for a new mission on the other side of the world, the threat of a major eruption of La Soufrière looms. The island is in dire straits, and Katia must ensure the safety of the population.