A Yale history professor travels back in time to 15th century France and gets stuck, unable to return to the present. His colleagues organize a rescue and on landing in France become involved in the Hundred Years War.
In the Nevada desert, an experiment has gone horribly wrong. A cloud of nanoparticles—micro-robots—has escaped from the laboratory. This cloud is self-sustaining and self-reproducing. It is intelligent and learns from experience. For all practical purposes, it is alive. It has been programmed as a predator. It is evolving swiftly, becoming more deadly with each passing hour. Every attempt to destroy it has failed. And we are the prey.
