From the very moment that Tom Swift Jr. agrees to help the government of Ngombia build a highway to link the jungle-separated provinces of the new African nation ñ a task that has stumped the best engineers in the United States -- he is beset by mysterious attacks aimed to defeat the project.

Construction of the road is urgent. At stake is the economic future of this friendly country. But no conventional highway will do. For existing engineering methods can not be used to bridge the seething, bubbling swamp in the rain forest.

Tom comes up with an amazing scientific solution to the problem -- an aerial highway over the jungle at treetop level, supported only by invisible repelatron beams.

Deep in the jungle, fantastic-sized creatures -- throwbacks to the dinosaur age -- and an eccentric scientist, missing for twenty years, add to the harassment's besetting the Swift work crews.

In a series of dangerous adventures, Tom must outmaneuver the sinister forces working against him and the Ngombian government, win the trust of the hostile scientist, and carry through the skyway to a successful conclusion.