This paper presents an explanation and illustration of the behavioural phenomenon of concretization through acting out. The phenomenon refers to the realization of fantasies and psychic conflicts pertaining to the traumatic past of Holocaust survivor parents, which might have been transmitted to the next generation narratively or beyond words. I have illustrated this phenomenon by material taken from the first stages of the analysis of a young man who shot and wounded his father during the latter's attempt to save him from suicide. The analytic experience facilitated the stabilization of ego boundaries and the emergence of a more secure sense of self.