Fourteen-year-old Celeste Marconi has finally returned to Valparaíso, Chile after living with her aunt in Maine in order to escape a brutal dictatorship. But the Valparaíso that Celeste returns to is very different from the one she left and she's determined to help her beloved Butterfly Hill rebuild and regain what was lost. But more than anything, Celeste wishes that she could bring back her best friend, Lucilla, who was one of the many children who disappeared during the dictatorship. As Celeste and her friends try to understand the terrible things that were done, she receives a letter that changes everything. As Celeste sets off to find her friend, she learns more about the heartbreaking events of the past few years and that moving forward and healing can make things better.