Naomi Armitage, her husband Ross, and their daughter Yoko are spending a nice, quite life in a nice part of Mars with new names. Unfortunately, troops have raided a Third Type facility slaughtering not only the Armitage robots, but killing the human staff as well. Now Naomi must cast off her duties as wife and mother and resume her role as unofficial detective. With political debate heating up over the issue of robots being given the same rights as humans, things have never been more dangerous for Naomi nor her family.
The trail leads Naomi to Earth and to Chicago while Ross is recruited to represent a Martian interest to participate in a vote for robot rights. However, with the introduction of two Armitage-type assassin robots, things have gone from bad to worse.