Nine-year-old Graciela is raised in the shadow of El Salvador's Izalco volcano, until the day she is taken to the capital city by the country's fearsome – and fearsomely superstitious – dictator, who believes her to be a muse capable of foreseeing the future. There, Graciela meets Consuelo, the sister she never knew existed.

Consuelo is everything she is not – volatile, dreamy and teenaged – yet despite their differences, the sisters form an unlikely bond. When the dictator's brutality is finally unleashed, El Salvador is forever changed. Graciela and Consuelo survive the massacre, but most of their community are not so lucky.

From San Salvador to Los Angeles, Paris to San Francisco, the sisters create a new future for themselves. But the story of those they left behind is not yet over. Their voices, once just a whimper, now shout louder than ever.