Attacks against Martian corporate interests within the colonies of the Solar System begin to escalate, leading to the Martian fleet enacting a systematic purge of resistance groups within the Core Worlds who may harbour members of the group calling themselves the 'Children of Earth'. The crew of the tramp freighter Erstwhile are on the run and soon find themselves drawn into a sequence of events which puts them squarely in the path of a plan to subjugate the people of the Core Worlds, devised and prepared for by the twisted Artificial Intelligence at the heart of the Children of Earth. With the very freedom of the Core Worlds at stake, Captain Maddox has to deduce the real reason behind the attacks and the AI's desire to return to Earth before it is too late, for both him and the free citizens of the inner worlds.