This novel began in discussions with Glenn Knight, while we were some thousands of miles apart. Jim Baen and Bernadette Bosky were of inestimable help in matters of direction. Karl Wagner—kindly old Doc Wagner—provided technical data as always. When my nerves were frazzled, Sharon Pigott spent an evening keying in the last of the rough draft and saving me a further day and a half of crushing work. And my wife, Jo, made friendly, dispassionate, enormously helpful comments on that rough.