Congo

The diamonds the company seeks are special blue stones that could transform computer technology, and a rival international group is racing to reach them first. The expedition travels by plane, parachute and on foot through dense forest, rivers and areas affected by civil war. Elliot has brought Amy because her drawings of nightmares seem to match ancient descriptions of the lost city of Zinj, and her skill with sign language turns out to be crucial.

Near an active volcano, the team finds the ruins of the city, and with them a group of unusually aggressive gray gorillas that seem to have been trained to guard it long ago. Amy attempts to communicate with them, and the team uses laser weapons, computers and clever improvisation to survive repeated attacks. A volcanic eruption adds to the danger. Crichton fills the book with technical details, maps and computer printouts, giving it a documentary feel, and he raises questions about the communication between humans and animals. There are violent scenes, but the pace is relentless.

Fast, inventive and gripping, later adapted as a film. About 496 pages in the Harper paperback.