On the way to the mountains the two friends encounter a hunter. Soon Ji-Stu witnesses the magic powers of Lake Ata-Gahi, which can heal the wounds of animals but is invisible to humans. As he sings and dances with the bears, Ji-Stu learns the magic of friendship as well as the magic of the lake.
Once the Fog started rising, the earth was covered with a deadly white mist until nothing remained but the mountaintops. Now humanity clings to its highest peaks, called the Rooftop, where the wealthy Five Families rule over the lower slopes and floating junkyards.
Thirteen-year-old Chess and his friends Hazel, Bea, and Swedish sail their rickety air raft over the deadly Fog, scavenging the ruins for anything they can sell to survive. But now survival isn't enough. They must risk everything to get to the miraculous city of Port Oro, the only place where their beloved Mrs. E can be cured of fogsickness. Yet the ruthless Lord Kodoc is hot on their trail, for Chess has a precious secret, one that Kodoc is desperate to use against him. Now Chess will face any danger to protect his friends, even if it means confronting what he fears the most.