British comedian legend Stephen Fry and zoologist Mark Carwardine travel from the Amazon's steamy jungles to New Zealand's icy mountain tops seeking some of the most remarkable and endangered creatures of Earth. Entertaining and informative with a unique insight into the fascinating world that we are in danger of losing. The two visit the Amazon in search of manatees, and find the pink boto dolphin (Inia geoffrensis) instead. While war in the Democratic Republic of Congo prevents discovery of the Northern white rhinoceros, (Ceratotherium simum cottoni), the hosts review the status of the Southern white rhinoceros (Ceratotherium simum simum) population on the Ol Pejeta Conservancy in Kenya. Their African sojourn continues with a tour of the Chimpanzee Rescue Sanctuary on Ngamba Island in Uganda, where chimpanzees (Pan troglodytes) are rehabilitated. Most of the chimps on the island have been rescued from poachers and the illegal exotic pet trade rampant in the DRC. On the day of their visit, two orphaned juvenile chimps, whose mothers were sold as bush meat, are introduced to an existing troop of adult chimps. The juveniles are immediately embraced by the troop, signaling a successful rehabilitation. Seeking out more apes, Fry and Carwandine trek through the Bwindi Impenetrable Forest in Uganda in order to encounter a family of mountain gorillas (Gorilla beringei beringei). These gorillas exhibit social grooming, feeding, chest-beating, and belch vocalizations. Heading to Madagascar, Fry and Carwardine hope to find wild aye-ayes (Daubentonia madagascariensis). After interacting with an aye-aye in a zoo, a local ranger helps the hosts find two adult wild aye-ayes, who have awakened in the middle of the night to feed on ripe coconuts. Employing percussive foraging, the aye-ayes use their long middle fingers to locate insects within tree branches. Fry and Carwardine also observe more of the numerous species of lemurs, which are exclusive to Madagascar. In the Berenty Reserve, researchers are conducting a long-term study of brown lemurs (Eulemur fulvus), surveying their feeding and mating habits and social interactions. On the reserve, they also observe ring-tailed lemurs (Lemur catta), dancing sifakas (Propithecus verreauxi), black-and-white ruffed lemurs (Varecia variegata), and the largest lemur on earth, the indri (Indri indri). The unique vocalizations of the indri make them easy to find in the vast forest. Examining the social interactions of these lemurs, Carwardine explains the traditions of female dominance among all lemurs. At a small field station, the pair observes the world's smallest lemur--the Madame Berthe's mouse lemur (Microcebus berthae). Examining the state of lemurs in Madagascar as a whole, Fry and Carwardine find that although new species of prosimians are constantly being discovered, they are becoming increasingly endangered due to deforestation and slash-and-burn agriculture. In an effort to reverse the damage done to Madagascar's forests, a team of local Malagasy is conducting a massive undertaking, replanting corridors of native trees so that lemurs and other animals can move between patches of rainforest. In the Malay Archipelago, the modern-day explorers assist in the conservation of sea turtles (Chelonia mydas) and komodo dragons (Varanus komodoensis). They also visit an area cleared for protected habitat for the proboscis monkey (Nasalis larvatus). The final two episodes find Fry and Carwardine in New Zealand searching out endangered birds and in the Sea of Cortez looking for endangered sea creatures.