Katie's world is shattered by the news that her headstrong and bohemian younger sister, Mia, has been found dead at the bottom of a cliff in Bali. The authorities say that Mia jumped. Although they'd hardly spoken since Mia left six months earlier, Katie refuses to accept that. With only the entries in her sister's travel journal as her guide, Katie retraces the last few months of Mia's life and - country by country - begins to uncover the mystery surrounding her death.