Eleven-year-old Vivian, kidnapped to far-distant future Time City by mistake, proves to be one of the City's saviors. Vivian Smith has gone to the West Country to escape the bombing of London at the beginning of WW II when she is unexpectedly met by imperious Jonathan Lee and whisked to Time City, which stands on its own piece of recycled time. Jonathan and his friend Sam explain that they had mistaken Vivian for the Time Lady, a mythical heroine or destroyer--their eavesdropping got muddled--who may be the cause of the deterioration of Time City. Convinced of their mistake, they pass Vivian off as cousin Vivian Lee. daughter of 20th-century Observers. The three bounce back and forth in time, trying to discover who is stealing the polarities, hidden by mysterious creator Faber John, that keep Time City whole. Aided by grouchy Tutor Wilander, android Elio, and a mysterious woman who saves Jonathan's life, they unmask Vivian Lee and her parents as the villians, reunite the pieces of Faber John and the pieces of the polarity, and save the city. As in earlier books such as Howl's Moving Castle, there is never a dull moment, with a new crisis or a new twist at every turn. While time-twisters never bear much scrutiny, Jones manages to resolve paradoxes and scattered clues without leaving the reader feeling cheated. Meanwhile, the book bounces merrily along, gathering momentum and generating dramatic tension. In all, a spirited, funny, and entertaining story.