This is the fourth book in a four book series.
The military fleet sent by the Starways Congress draws closer to Lusitania. The intelligence named Jane living in the ansible communication system begins transporting the sentient life forms off Lusitania to other distant worlds using her new found method of instant space travel over any distance.
But time is running out for Jane and those she would save. In an effort to purge her from the network, the Starways Congress is shutting down the system planet by planet. Without enough processing power she will not be able to make the jumps. Soon after that, she will die.
Mean while Peter Wiggin and Si Wang-Mu set off on a journey to try and persuade the Congress to call off the fleet.