Predator

Predator is the second volume in the Robots in Time series by American science fiction writer William F. Wu, a series built on Isaac Asimov's Three Laws of Robotics and ideas of time travel, and approved by Asimov himself. The story takes place around 2140: the mayor of Mohave Center is the most advanced experimental robot of the time, composed of six independent units and capable of managing a robot city on its own. Sensing that a design flaw in itself could lead to destruction, it invokes the Third Law of Robotics—a robot may protect its own existence—and disassembles itself into six parts, sending them into the distant past. But it does not know that crossing time alters molecular structure, and if the pieces are not retrieved in time, they will trigger nuclear explosions in past eras and permanently rewrite human history. The experimental robot Hunter is ordered to assemble a team and, together with a robotics expert, a paleontologist, and a companion skilled in wilderness survival, travels to western North America in the Cretaceous period some sixty million years ago to find and capture the first missing unit in a savage world roamed by dinosaurs. This volume tells precisely of that hunt in prehistoric Earth, centered on the "Predator": they must bring the target robot back before the explosion, and once they return to the present, a new crisis is already brewing elsewhere.