The laws of robotics

1. A robot may not injure a human being, or through inaction, allow a human being to come to harm.

2. A robot must obey the orders given it by human beings, except where such orders would conflict with the First Law.

3. A robot must protect its own existence, as long as such protection does not conflict with the First or Second Law.

This novel is dedicated to

The memory of my paternal grandfather, Yuan San Wu, who passed the story of the building of the Great Wall to me through my father

Special thanks are due during the time of writing this novel to Dr. William Q. Wu and Cecile F. Wu, my parents, for indulging my lifelong interest in history; Ricia Mainhardt; Robert L. DeCandido of the New York Public Library (Research) Preservation Division, for assistance with the descriptions of papermaking; and John Betancourt, Leigh Grossman, Keith R.A. DeCandido, and Byron Preiss