There's something very strange going on at Withering Mansions Boarding School ... On Tuesday, Cal's mother, Professor Zoe Riddle, mysteriously vanishes. On Wednesday, Aunt Alice Riddle, a relative Cal never knew he had, suddenly appears as a new teacher at the school. And that's not all. Strange accidents are happening; and Aunt Alice is becoming odder by the moment. Not surprising, since Cal discovers she's an android sent from the future! She is instructed to find out how to rescue Cal's mother who's invented a time machine and is now stuck in 2070. Cal's in terrible trouble. His friends are asking awkward questions, Aunt Alice has only the vaguest idea of how to act like a human, and someone seems determined to destroy any chance of Cal's mother returning to the present day.