When Russell Stone becomes the teacher of a young Algerian woman with a disturbingly luminous presence, he is both entranced and troubled. How can this refugee from terror radiate such bliss? Is it possible to be so open and alive without coming to serious harm? Soon, Thassa's joyful personality comes to the attention of the notorious geneticist and advocate for genomic enhancement, Thomas Kurton, whose research has enabled him to announce his discovery of the genetic underpinnings of happiness. Thassa's congenital optimism is severely tested by the growing media circus. Devoured by the public as a living prophecy, her genetic secret will transform both Russell and Kurton, as well as the world at large.

Generosity is fast, funny and finally magical. In his most exuberant and exhilaratingly brilliant book yet, Richard Powers asks his readers to consider the big questions facing humankind as it learns of the genetic map underlying every aspect of our existence