In a time like the present, in a world that may or may not be our own, three young people–Ginny, Jack, and Daniel–dream of a decadent, doomed city of the distant future: the Kalpa. But more than dreams link these three: They are fate-shifters, born with the ability to skip across the surface of the fifth dimension, inhabiting alternate versions of themselves. And each guards an object whose origin and purpose are unknown: gnarled, stony artifacts called sum-runners that persist unchanged through all versions of time. Hunted by others with similar powers who seek the sum-runners on behalf of a terrifying, goddess-like entity known as the Chalk Princess, Ginny, Jack, and Daniel are drawn into an all but hopeless mission to rescue the future–and complete the greatest achievement in human history.

Книга повествует о Кальпе, последнем городе на Земле в конце времен, и его обитателях.

Остатки человечества сражаются с метафизической напастью, которая угрожает исказить всю историю...