Through a clinical sequence involving an adolescent who presents himself as blind, the article shows the transmutation of an inability to constitute an horizon of the subjective world into a capacity, retrieved in the transference, for subjectivating (himself) from a traumatic point and for setting up the theater of an intimate world. The therapeutic progress begins from traces of the body’s being grasped, and sustains itself on the equivocal diagnosis attesting to both the blind alley and the attempt to exist. The question is then successively, to point out the blind alleys of the subjectivation of the adolescent passage, to provide living metaphors able to serve as primers for symbolization, to restore progressively the capacity to organize a view of the world and of oneself, to face what has happened, and finally to open a new subjective reality.