These are memories by a Polish Jew of his childhood from 1939 to 1948, during which he was rounded up for extermination with his family, whom he never saw again - he thinks he had four brothers, but cannot be sure. His father was killed in front of his eyes, his brothers vanished, while he himself somehow survived a series of death camps.
Rescued from an orphanage in Cracow after the war by a Swiss-born widow, he acquired foster-parents who seem to have meant little to him and who kept telling him to forget his past life as a bad dream. Obviously, he could not and did not do so. His book (written originally in German) is precisely what the title says - fragments, producing a strange sense of dislocation and surreality.