What shall I do?"" --is the agony of an honorable, educated German family in Hitler's Reich during and after World War II; who is guilty- is the problem of everyone. The story is told from the point of view of young Mark, torn between the fanatical loyalty to the Fuehrer he is taught at school and the moderation, even contempt, he hears at home. But it is properly a family chronicle: Mark is device, a sounding board for the most part--this elders must make and justify their choice. In the years between 1939 and 1946 they are never Nazis--they shelter a scholarly uncle who resigned his university post in protest against restrictive decrees, assist their Jewish neighbors until they are ""relocated,"" give aid and comfort to an anti-Nazi movement; they do whatever they can quietly that will not put them in direct conflict with the authorities. At war's end, they reject the presumption of collective guilt and it is chiefly Mark--learning he is an adopted Polish orphan--who must make the conscious decision to assume responsibility for the German future. The author personifies philosophical positions, turns them about and challenges them, with a thoroughness and subtlety rare in juveniles: one can only admire her purpose and her method, whether or not one agrees with all her conclusions. The weakness of the book as historical fiction (it is based on real events and incorporates several real personages) is the weakness of Mark, especially as young boy, and his role as a sometimes mysterious pawn. Young people are not likely to identify with Mark, but the more serious among them cannot fail to be caught up by the tragedy--and occasional irony--of a continuing crisis of conscience.