This article focuses on the correspondences of Isabelle Eberhardt (1877-1904) already published and those unpublished from the Archives Nationales d'Outre-Mer d'Aix-en- Provence. It aims at understanding her intercultural itinerary. Through the widespread por- trait of a nomad of the extreme who breaks definitively with European culture to adopt that of her chosen land, Algeria, we will see that it is necessary to reassess the motives of her fascination for the Arab-Muslim elsewhere. Her intimate correspondence confronted with her open and committed letters will bring to light contradictions which will lead us to note that she will never become totally Other. We will finally consider her as a “passeuse” between cultures and an intellectual nomad (Kenneth White). She nomadizes between cultures and gleans the best in each for a creative synthesis. Her existence and correspondences open onto a world and a poetics of the in-between, of the nuance and the association of opposites in harmony with her person and with the inherent diversity of the Mediterranean space.