The author analyzes the mechanism of suicidal constructions in adolescence. This conduct is an avatar of the initiatory fantasy of the return of the originary in adolescence : self-engenderment in the presence of at least one other person and its opposite, self-destruction in the presence of at least one other person. He shows how the adolescent summons the intruder into his psychical dynamic of scenality/obscenality by confronting at least one other person with the terror of death. If the other or others who are terrified remain present, the adolescent can think that despite the intrusive terror that fills him he remains human. In the case of the contrary, suicidal or murderous conduct can result. The entry into adulthood requires that the adolescent confront a necessary death, one which inscribes him as mortal, part of humankind ; and a death that is sufficient for him to go beyond eternal objects of infantile loves and be able to invest in bonds of desire with perishable love objects.