Margaret Peterson Haddix (author) Jonah and Katherine are sitting in class when time freezes. Everyone, everywhere in the twenty-first century is frozen in time - except for those who have traveled in time before. Something is catastrophically wrong, but what, and how can they fix it? Jonah and Katherine barely have a second to talk to JB before they find themselves hurtling back in time again. They end up in 1903, where a botched job of returning Albert Einstein's secret daughter, Lieserl, has somehow critically damaged time itself. Jonah and Katherine have their work cut out for them, working to set right a problem they can't understand. And there's another wrinkles in their plans: Even though the Elucidator has made them invisible, Lieserl's mother, Mileva Einstein, seems to have caught on to their presence and their plans. And she is determined not to let them take her daughter. In the fifth book in her New York Times bestselling series, Margaret Peterson Haddix raises the stakes far beyond anyone could have imagined.