Psychic trauma is characterized by ego damage, regression, and relative helplessness. Following a historic catastrophe, psychic trauma with ego damage is frequently encountered as cumulative trauma. Reconstruction was essential to the understanding of an adult patient initially unaware of his holocaust trauma. When the patient was a child, he and his parents were simultaneously traumatized. Intrapsychic intergenerational psychosocial and neurobiological factors were adverse codeterminants of his cumulative trauma. Isolated affects and fragmented memories required sequential connection in the context of family, identity, and society. Reconstruction importantly contributed to ego reintegra-tion of a lost, lacerated childhood, and to adaptive mastery of trauma and conflict.