The story is told by the protagonist, Marion Stone. He and his conjoined twin Shiva are born at Mission Hospital (called "Missing" in accordance with the local pronunciation), Addis Ababa, in September 1954. Their mother, Sister Mary Joseph Praise, an Indian Carmelite nun, dies during childbirth. Their father, Thomas Stone, the English surgeon of Missing, abandons them and disappears.
Orphaned at birth, the pair grow up in the household of two physicians of Missing, both from Madras, the obstetrician Kalpana Hemlatha (Hema) and Abhi Ghosh, who fall in love while caring for the infants. Hema names them Marion (after J. Marion Sims) and Shiva (after the Hindu deity). Ghosh teaches himself surgery to replace Stone. The tissue link between the twins has been separated at birth and the two grow up together being very close initially.
Both are exposed to the changing political environment in Ethiopia. There is an unsuccessful rebellion by Haile Selassie’s bodyguard, General Mebratu. Ghosh is imprisoned, then released, in the aftermath of the coup, due to his friendship with Mebratu. Through their parents, both boys are exposed to medicine and taught at the hospital. Over time, though, individual differences begin to become pronounced. When entering puberty their relationship to Genet, the daughter of Rosina, a domestic help, finally tears them apart. Marion is in love with Genet and intends to marry her, but it is Shiva who, interested in sexual pursuits, deflowers her.
Marion feels betrayed. Rosina forces Genet to submit to female genital mutilation and commits suicide shortly thereafter. Genet will later join the Eritrean liberation movement. While Marion goes to medical school, his brother stays at Missing. Focused on the repair of birth-related fistulas, he takes up his surgical training with Hema eschewing a formal medical education. On his death bed, Ghosh has three wishes for Marion - to get the best medical education, to find Stone, and to forgive his brother.
When Genet and her comrades hijack an Ethiopian Airlines airplane in 1979, Marion is on a list of her connections. To avoid arrest he flees the country overnight to Kenya. He goes to New York where he finds a position at Our Lady of Perpetual Succour, a hospital in the Bronx. There, he enters a surgical residency. One day, assisting his senior in a complicated trauma operation, an unknown surgeon enters looking them over the shoulder. It is Thomas Stone, by now a well-renowned liver surgeon from Boston. Marion’s encounter with his biological father redirects his life leading to a painful reconciliation and reunion with his estranged brother.