A unique blend of medical thriller, science fiction, and suspense by Robin Cook. Unlike many of Cook's hospital-based thrillers, Invasion ventures into extraterrestrial territory while retaining the scientific realism and tension for which he is known.

The story begins when mysterious black discs fall to Earth following what appears to be a meteor shower. Soon afterward, people who come into contact with the objects begin displaying strange symptoms and dramatic changes in behavior. As the phenomenon spreads, scientists and medical professionals uncover evidence of an alien organism with the potential to transform humanity on a global scale.

At the center of the crisis are medical experts and researchers racing to understand the nature of the threat before it overwhelms civilization. What starts as a scientific mystery evolves into a desperate battle for the future of the human race.

Combining medical science, alien invasion, biotechnology, and fast-paced suspense, Invasion is one of Robin Cook's most imaginative and unconventional novels.