Certain catastrophes in certain children can forever change biology by creating and maintaining early warning systems, perpetual wariness, in a world that, long afterwards, remains ever hazardous and threatening —in which the demons of nightmares become real. The presence or persistence of post-traumatic symptoms need not outweigh the healthy capacity to live. Child psychiatrists can sometimes provide a road map, without shortcuts, toward the resumption of travel in the right direction. (11 pp.)