Saving the world

Latina novelist Alma Huebner begs off joining her husband on a humanitarian mission to the Dominican Republic to work on her next book, and finds herself becoming obsessed with the life of her subject--a woman who hand-picked a group of orphan boys to serve as live carriers of the small pox virus in order to provide Spaniard Francisco Xavier Balmis a ready supply of vaccine with which to inoculate the populations of Spain's American colonies in 1803.