The war with the Arduans - profoundly alien invaders who originally arrived in STL ships - is over. Most of those attackers are now probationary (and very productive) citizens of the Rim Federation. However, many among the Arduans' warrior caste have accepted neither defeat nor the personhood of any of the other intelligence races. Their leader, the ruthless admiral of the second Arduan exodus, Amunsit, is in firm control of the Zarzuela system.

The war with the profoundly alien Arduans has ended, and the Arduans have come to call humanity their allies. Most of them - the Arduan warrior caste refuses to accept defeat. Now known as the Kaituni, they are waging a war of extermination against all members of the pan-Sentient Union, human and Arduan alike. What's more, the Kaituni have an unexpected weapon in their arsenal: the alien Arachnids, once thought driven to extinction. The Kaituni drive the Arachnid fleet ahead of them, inflicting untold damage.

The mind-numbingly alien Arachnids were an enemy whose like no civilized race had ever confronted. Like some carnivorous cancer, the "Bugs" had overrun planet after planet...and they regarded any competing sentient species as only one more protein source. They couldn't be reasoned with, or even talked to, because no one had the least idea of how to communicate with a telepathic species with no recognizable language...and whose response to any communication attempt was a missile salvo.

Long ago, much of the population of an entire planet fled their world before its sun went nova in thousands of ships, each one larger than a city. Now, the armada has arrived at the world they intend to make their new home. They regard the fact that the planet is already colonized by humans as a mere inconvenience, and their mode of communication is so different from anything humans use that they do not consider humans and their allies to be truly intelligent.

Spacers call the warp point Charon's Ferry. No star ship has ever entered it and returned since a vengeful Orion task force pursued a doomed Terran colonization fleet into it in 2206. Almost a century has passed. The fiery hatreds of a quarter-century of warfare between the Terran Federation and the Zheeerlikou'valkhannaieeee, the cat-like species humans called the "Orions", have eased at least a little.