Paul Bannerman, an ecologist in South Africa, believes he understands the trajectory of his life, with the usual markers of vocation and marriage. But when he's diagnosed with thyroid cancer and, after surgery, prescribed treatment that will leave him radioactive, for a period a danger to others, he begins to question, as Auden wrote, "what Authority gives / existence its surprise."

In the garden of his childhood home, where his businessman father, Adrian, and prominent civil rights lawyer mother, Lyndsay, take him in to protect his wife and child from radiation, he enters an unthinkable existence and another kind of illumination: the contradiction between the values of his work and those of his wife, Benni, an ad agency executive. His mother is transformed by the strange state of her son's existence to face her own past. Meanwhile, projects to build a nuclear reactor and drain vital wetlands preoccupy Paul as if he were at work. By the time he is cured, both families have been changed. On his return to his home and career, his parents go to Mexico to fulfill the archaeological vocation Adrian sacrificed to support his family. The consequence of this trip is the final surprise in this extraordinary exploration of passionate individual existences.