This chilling novel, which was later made into a film starring Gregory Peck and Lawrence Olivier, has genre elements of both science fiction and political thriller. Published in 1976, the book draws upon the nascent technology of cloning to imagine a world in which Hitler could be brought back to life. A young investigative journalist named Barry Kohler learns of a "project" happening in Brazil, headed by Josef Mengele, one of Hitler's operatives, who, in this fictional version of history, survived the Third Reich and is preparing to create a Fourth Reich. Mengele was believed to be the mastermind behind the worst forms of torture and cruelty in the concentration camps, and was dubbed the "Angel of Death."

Kohler has been researching the story for years but has had to be careful not to attract the attention of the people he's studying. Kohler contacts a famous "Nazi hunter" named Ezra Lieberman to help him expose this operation, but Kohler is killed before he can deliver more concrete facts and evidence. Thus Lieberman has to chase down the conspiracy himself, and as an elderly man, this is both difficult and frightening, but is also exhilarating for a man who himself lived through the anti-Semitic hatred of the war.

The basic structure of the conspiracy is that a number of embryos of baby boys are created/cloned using some of Hitler's genetic material, and these babies are then placed in family situations resembling Hitler's own upbringing. They are placed throughout the world, in different countries. Lieberman makes it his mission to hunt them all down and kill them as mercifully as possible so that this monster will not rise to power.

Eventually, there is only one boy left, living in the United States. There is a final face off between Mengele and Lieberman at this boy's home. Their battle is a masterful exchange between two brilliant men who clearly respect each other's intelligence, but the hatred Mengele feels for Lieberman's ethnicity, and the hatred Lieberman feels for Mengele's horrific crimes motivated by bigotry, make it clear that this will be a fight to the death. Fortunately, Lieberman barely survives, and it seems that possibly the last of the "boys form Brazil" will be eliminated. The boy is a movie buff who trains his German Shepherds as attack dogs, using commands related to movie production like "action" and "cut." He doesn't really understand the conspiracy behind his origins, but the novel clearly portrays the child as having sadistic and violent tendencies, thereby justifying Lieberman's tactics.