Cruising in his seventy-five-foot yacht Miami, off northern Newfoundland, young Tom Jones is hijacked by gangsters, whose boat, engaged in gun-running from Canada to Central America, was sinking. Scarface Boston Jimmy, chief of the gun-runners, takes command of the Miami, which is driven northward by terrific storms, and finally is caught in the polar ice. An opening in the ice, leading northward, leads them over the edge of the world, and they find that the story of the Radio Flyers was true. There is a huge opening into the inside of the earth, which is a hollow shell with a small central sun. Here the explorers find land-the land of Vikings, Skraelings, dinosaurs, and Angus Silkirk and Eric Redmond, the Radio Flyers. A sequel to THE RADIO FLYERS.