Jeorling, a wealthy American, has entertained himself with private studies of the wildlife on the Kerguelen Islands and is now looking for a passage back to the USA. Halbrane is one of the first ships to arrive at Kerguelen, and its captain somewhat reluctantly agrees to have Jeorling as a passenger as far as Tristan da Cunha. Underway, they meet a stray iceberg with a dead body on it...
In 1881, Joam Garral, a ranch owner who lives near the Peruvian-Brazilian border on the Amazon River, is forced to travel down-stream when his past catches up with him
Professor Von Hardwigg believes there are volcanic tubes going toward the center of the Earth. He, his nephew Axel, and their guide Hans encounter many adventures, including prehistoric animals and natural hazards, eventually coming to the surface again in southern Italy.