Congo

The novel follows an expedition led by Karen Ross to the dense tropical rainforest of the Congo to investigate the mysterious deaths of a previous team and to find the lost city of Zinj, where valuable type IIb diamonds are believed to be located.

The team includes Peter Elliot, a gorilla researcher, and his sign-language-trained gorilla, Amy. They face numerous challenges, including rival expeditions, civil wars, and dangerous jungle predators.

The story blends elements of science fiction, adventure, and technological intrigue, reflecting Crichton's signature style of combining science, technology, and action.