With their mysterious leader, Font Prime, silenced, the robots have fallen under the baneful influence of Kaantur-Set, who directs a program of human extermination. But the robots themselves are on the point of extinction, as their technologies of reproduction no longer work.
With Font Prime silenced, the robots are now controlled by Kaantur-Set and are being used to carry out a plan to exterminate humans.  The robots' own ability to reproduce is failing, leading to their imminent demise.