While Alma Huebert is researching a new novel, she finds her real story—and her salvation—in a little-known but staggering historical footnote: the Royal Expedition of the Vaccine. In 1803, Don Francisco Balmis embarked on a two-year sea voyage to rescue the New World from smallpox. Accompanying him were twenty-two orphan boys, acting as live carriers, and their guardian, Isabel Sendales y Gómez. As Alma digs deeper into Isabel's life, she finds her own power to commit an act as life-changing as Isabel's.

In Saving the World, Julia Alvarez, author of perennial bestsellers, including How the García Girls Lost Their Accents and In the Time of the Butterflies, takes us into the worlds of "two women living two centuries apart [who] each face 'a crisis of the soul' when their fates are tied to idealistic men" (Publishers Weekly).