Sarah's prospects for finding her family have never looked dimmer than they do today. Enslaved by the City of the Children, she and the other adults are at hard labor for their youthful captors, excavating leaky canisters of deadly radioactive waste from an icebound mine. The teen-aged overseers' maltreatment of another prisoner forces her to make an impossible choice: she can turn a blind eye or she can put her own life -- and her quest -- on the line by tangling with the mysterious Mother of the City of the Children.