On January 27, 1968, the submarine "La Minerve" sank off Toulon with 52 crew members on board. For more than 50 years the disappearance of this submarine has remained a real mystery. It was not until July 2019 that the building was found off the coast of Toulon, following new research undertaken by the Ministry of the Armed Forces. It lies at 2,370m deep, 45km off Toulon. Hervé Fauve, the son of the last commander of "La Minerve" testifies. It highlights the many years of investigation. Technical breakdown, collision, beginnings of nuclear war? How did this giant of the seas take more than half a century to be found? Investigation of what appears to be a state affair.