The Hoggar, an unexplored chain of montains that marked the limits of European exploration into the Sahara Desert at the beginning of the century, serves as the background for the dramatic moment when a young officer named Saint-Avit saves the life of Lieutennat Morhange of the Geographical service. After the rescue from the Tuaregs, the two men form in an intense friendship that is made even stronger through the passion they share for the mysterious Amira. Their professionnal and private lives are played out against an exotic charm of the casbah. Then, one day when out on patrol in the desert Saint-Avit discovers a cross engraved in the rock, a cross formed by a word from the mysterious Tifinar language: Antinea... maybe a sign of past life... But there's no trace of the expedition...