Amazon Adventure Hal and Roger Hunt crash-land into the middle of a pioneering expedition to the unmapped regions of the greatest jungle on earth: the Amazon.
South Sea Adventure Hal and Roger Hunt sink deep into danger when a specimen-collecting trip takes them into the lost world of the South Seas.
Underwater Adventure Hal and Roger Hunt dive into danger when they join the Oceanographic institute as part of an underwater operation in the South Seas.
Volcano Adventure Hal and Roger Hunt embark on an earth-shattering expedition when they join forces with world-famous volcanologist Dr Dan Adams.
Whale Adventure Hal and Roger Hunt are hoping to have a whale of a time when they agree to join the crew of a whaling ship.
African Adventure Hal and Roger Hunt are on the trail of a vicious man-eating leopard. Yet they are also being hunted themselves, by a merciless band of killers known as the Leopard Society.
Elephant Adventure Hal and Roger Hunt are on an awesome African adventure to track down the rare great white elephant. The brothers coolly tackle their task - despite doom-laden prophecies from mumbo, a Watussi chieftain - and as the temperature rises . . . the danger-level intensifies.