This novel interweaves facts about the history of genetics with compelling fictional characters and plots in two connected stories. The primary story traces the life and work of the fictional Benedict Lambert, brilliant 20th Century geneticist, and an achondroplastic dwarf; his research is to discover the gene mutation which has caused his condition. He is also the great-great-great nephew of Gregor Mendel.

The life and genetic work of Gregor Mendel comprise the second story. Intersecting with Gregor Mendel's 19th Century scientific experiments to artificially fertilize pea plants is Lambert's affair with married librarian Jean Piercey. When Jean becomes pregnant, she decides on termination after learning from Benedict that there is "a fifty-fifty change of ending up like me . . . a second Benedict, another squat and crumpled creature betrayed by mutation and the courtly dance of chromosomes . . . " (180).

By the novel's end, Mendel's work has been published, and dismissed; Benedict Lambert has discovered the location of the gene mutation which causes achondroplastic dwarfism, publishes the results in Nature, and is asked to make a presentation on "the New Eugenics". Jean regrets the abortion, and wants Benedict's child, but a ?normal" one. In an attempt to help Jean in her quest, Benedict uses his genetic knowledge, his laboratory privileges, and his sperm without the knowledge or consent of Jean's husband.

In the lab with eight of Jean's fertilized embryos Lambert must decide: "Four of the embryos are proto-Benedicts, proto-dwarf; the other four are, for want of a better word normal. How should he choose?" The results of this scientific and personal act of fertilization are unexpected and tragic.