BOOM! A violent explosion shatters the calm Minneapolis air, interrupting the evening walk of Walter Fisk and Polly Stevenson, and their friends Anton and Brita. Pieces of glass, wood, and concrete fall around the children, and black smoke rises from the mill where Brita's father works. Ten men are dead, and Brita's father is seriously hurt. Will Brita's father survive? And how can Walter and Polly help their friend if she has to leave school and...