The memoirs of a minor, reluctant, but guilt-ridden Nazi war criminal: Dr. Peter Langhof, now elderly, who lives on a South American estate with pathetic old colleague Dr. Ludtz--and who recalls the past while waiting for the annual visit of ""El Presidente."" (In return for diamonds--death-camp booty--the dictator protects Langhof and Ludtz from Nazi-hunters.) In fragmented vignettes, then, Langhof recalls his passive path into monstrous evil: his disillusioned father's post-WW I suicide; his loss of first-love Anna; his non-Nazi alienation in the '20s (""He stood between a broken world and the maniacal schemes that claimed authority and competence to rebuild it""); his pursuit of purification through the study of hygiene; his cynical, gloomy reactions (stopping short of protest) to Nazi practices; and his assignment to ""the Camp,"" where he numbly assisted in the most hideous of pseudo-medical experiments (""He took upon himself the revery of the void, the romance of nihilism and absolute estrangement""). . . until friendship with sardonic prisoner Ginzburg at last pushed him over the edge into belated rebellion. Meanwhile, however, narrator Langhof also meditates on the evil of El Presidente--who is fighting rebel guerrillas with help from Langhof's diamonds (which were given to Langhof by Ginzburg in the Camp). And finally, after the death of trembling, fearful old Dr. Ludtz, Langhof will put an end to his support of El Presidente's evil. . . though he knows this will bring about his own end: ""I will wait on my verandah and perhaps allow myself to dream--as some men do--of that far world where no man's mind can long be held within an orchid's dome."" Throughout, in fact, Cook marbles Langhof's musings with such quasi-poetic imagery (orchids, diamonds, stars, etc.); he also allows him to indulge in pretentious ruminations--""Imprisoned in the I, we clothe ourselves in the robes of predictability. . .""--that fail to illuminate Langhof's entrapment by Evil. And the result is an often-unconvincing psychological portrait. Still, much of Cook's plainer writing is grimly effective (especially in the ghastly death-camp scenes)--and, however familiar, the central premise here is strong enough to pull readers along through this talented, uneven essay-novel.