Olivia thought that her adventuring days in the extraordinary, mystical world of Theia were over. However, despite the best efforts of Hector, the History Keeper, five of the History Sphere’s discs are damaged. Hector has no choice but to ask for Olivia's help again – but the warlock Gillespie is determined to defeat the Earth girl's efforts. From Shakespeare’s Globe theatre to the Paris of Louis Braille, from Alexander Fleming’s London to Nazi-occupied Warsaw and the Deep South of Rosa Parks, Olivia travels through time and space to prevent historical disasters. Accompanied by her otherworldly friends and her two loyal terriers, she encounters terrifying adventures and life threatening magic. Will she succeed in her mission and prevent Gillespie altering the course of history?