It was in Venice, in 1911, that we met Corto with a journalist from the National Geographic, Aida Treat, who wished to make his portrait. He was then on the track of a mysterious artifact, The Mirror of Priest John. His investigation quickly directed him to Alexandria. During the crossing, he met a beautiful German of Somali origin, Ferida Schnitzer, and his chaperone, the imposing Sister Lise. Arriving in Egypt, where he rescued Winston Churchill from an attack by the nationalists, he decided to embark with Henry de Monfreid for Zanzibar, where he hoped to find the trace of the mirror in a famous slave trafficker.Then he would sink into the jungles of equatorial Africa in search of Ferida's father, a German explorer who had disappeared in the area some twenty years earlier.