When Tara's beloved grandmother Claire dies suddenly in a car accident, she is devastated. Her mother becomes depressed and uncommunicative, and her wild sister Riley wants to run off to California to live with their father. Luckily, her grandmother has made provisions in her will for the family to be taken care of, and a family retainer, Butler Reginald, comes to help Tara follow the clues and keys that her grandmother has left her. She goes from her decrepit Southern mansion home to her grandmother's equally decrepit house, and from there to her grandmother's research facility on the island of Chuuk in Micronesia. Everywhere she goes, gorgeous butterflies follow her. With the help of one of her grandmother's assistants, Eloni, she uncovers a huge secret related to the butterflies, as well as an evil plot that she must foil in order to keep her grandmother's butterflies safe.
Tara is a sympathetic character, and her grief for her grandmother is tempered by her worry and disgust at her mother's failure as a parent. There are lots of clues and puzzles that Tara needs to figure out that lead her to find out more about her grandmother's work with the butterflies. It's fun that she gets to travel around, with the bare minimum of adult supervision. There's also a lot of twists at the very end of the book that I don't want to give away.