For 578 million years the Galactic Core was controlled by the malevolent realm called Garadhros. The power of Garadhros was maintained by the Gergathan, an immesnely- sophisticated war computer whose inflexible rule pervaded every level of the society.
Twenty-two million years before our time, and a million years before the events of The Circle Mark'd by Heaven,Garadhros was defeated by armies from the Virgo Cluster of galaxies. Virgo's champions were the Warriors of the Honorable Retribution -- a corps of over eight thousand cyborg volunteers, part biological and part mechanical, able to survive in virtually any environment and to attack by any means. After a terrible battle, Garadhros was conquered and the Gergathan destroyed. The cost was tremendous: over seven thousand Warriors of the Honorable Retribution perished, and the Virgan culture, exhausted, fell into a long, slow decline.
The million years that followed were peaceful ones for the Scattered Worlds of the Milky Way Galaxy. The Virgans withdrewto their own distant cluster. Under the enlightened guidence of the Hlutr and the Daamin, many of Garadhros' subject races found true maturity. The interstellar brotherhood of the Galacitc Riders prospered, and the planet Nephestal blossomed as the cultural center of the Galaxy.
The Singing Stones -- unique telepathic amplifiers which focussed and rebroadcast the sum total of all thought and emotion in the Galaxy -- produced the clearest and most profound melodies heard in ages. On Nephestal a new class of creatures arose among those who were particularly sensitive to this mental music, particularly adept at unravelling its component strands to gain new knowledge of the cosmos. They called themselves the Watchers of the Stones, and their vigil continued for generations.
One by one, the Warriors of the Honorable Retribution went to sleep, or conquered other universes, or simply departed on their own concerns, until they were known in the Scattered Worlds no more.
The Daamin, the weird masters of Nephestal, sought to breed a race superior in intellect and physical ability to any other; the strange, ethereal, racially paranoid Ashtoki were the result of their experiments.
A million years passed -- a thousand times a thousand years: enough time for civilizations to rise and fall, new races to be born, and the ancient threat of Garadhros and the Gergathan to be forgotten....
The Gergathan has reawakened, and is out for conquest. Unfortunately, this is not yet known by the Scattered Worlds or the Virgo Cluster, and Delger 453542281 is determined to keep the secret until his master is strong enough to defend itself against its enemies.
The story opens on Nephestal, as Lirith detects the hibernating Jel Haran, who has been floating in space since the defeat of Garadhros. She brings him back to Nephestal, where Daamin doctors reawaken him. Unable to repair the damage to his cyborg body, they give him a body similar to Lirith's. The two begin to fall in love, and look forward to a lifetime of peace.
Meanwhile, Otton Wo -- Lirith's fellow Watcher -- has been up to no good. Through the Singing Stones he has made contact with Kulec Mixatl, the commander of a military base on the moon of the planet Mamaukl. Mamaukl was recently destroyed in a nuclear war; Kulec Mixatl's people launched the missles that started that conflict, on orders of their superiors. Now they are all that's left of their race. When Otton Wo first contacted them, their community was in complete despair; now Otton Wo realizes that he can use them for a mission of his own.
Through the Stones, Otton Wo has discovered what he thinks is the fabled Wem L'teff, the ultimate weapon of the Warriors of the Honorable Retribution. The Wem L'teff is a device which "unravels" the fabric of space, thus destroying everything it touches: the Gergathan wants the Wem L'teff as a defense against any further attack by the Warriors; Delger has promised Otton Wo great wealth and power if he will secure the device.
The Wem L'teff is buried deep in the ocean of the planet Witaxicul-3...which is the Earth of twenty-one million years ago. Otton Wo convinces the Mamauklans to move to Witaxicul-3; he hopes that they will be able to secretly retrieve the Wem L'teff for him.
Unfortunately, Witaxicul-3 is inhabited by a sapient race, the Forcora -- the ancestors of today's whales.
Lirith detects Otton Wo communicating with Kulec Mixatl, and although she does not divine the details of his scheme, she senses something fishy. She and Jel Haran visit Witaxicul-3 but find no reason for concern: the Mamauklans seem to be settling in well on their new home. Back on Nepehstal, Lirith and Jel Haran are joined in the Scattered Worlds equivalent of marriage. Then the two set off together to Virgo so that Jel Haran can see his people.
Meanwhile, the Mamauklans...under Otton Wo's guidence...have begun searching for the Wem L'teff. In the process, they learn to hunt the peaceful Forcora, and a war begins between the two races.
Quietly, the Gergathan declares a new realm named Diebethar, and moves through proxies to annex several nearby planets. The Scattered Worlds are unconcerned, since to them these annexations look like the typical squabbling of developing races.
Lirith, however, detects the thoughts of the Gergathan and departs Virgo immediately to return home. Jel Haran remains behind, trying to convince the Virgans to build more Warriors and prepare for another war. But a million years of decline have done great damage to the Virgans, and they are reluctant to get involved again.
Lirith travels to Witaxicul-3 and is disturbed; she asks the Council of the Free Peoples of the Scattered Worlds to act against the Gergathan. Otton Wo dismisses her suspicions as Ashtoki paranoia, and convinces the Council to do nothing.
Jel Haran returns from Virgo just in time for the first military engagement between Diebethar and the Scattered Worlds; frightened by the Gergathan's power, he reluctantly sheds his Ashtoki body and takes on his Virgan Warrior form again.
The situation on Witaxicul-3 has deteriorated further -- now the Mamauklans have split into two factions, and nuclear annihilation threatens the world. Delger, watching from afar, is delighted: he has the Wem L'teff, and when the Mamauklans and the Forcora are dead, Otton Wo will be the only remaining witness. And Delger intends to kill Otton Wo as soon as the war is concluded.
Lirith goes to Witaxicul-3 in a last attempt to make peace, and Jel Haran departs for Virgo Cluster to get help. But Delger captures Jel Haran and takes him to the Gergathan.
Lirith finds Otton Wo waiting for her, and confronts him within the mental landscape of the Stones; after a surreal fight she defeats him and stops the war, then sets off to rescue Jel Haran from the Gergathan.
Jel Haran, captured and tortured, confronts Delger; the two are counterparts, each in the service of an ideal completely opposite that of the other. But Jel Haran tries to convince Delger that the Gergathan is evil.
When Lirith finds Jel Haran all but dead, she is angry and tries to use the Wem L'teff -- but at the last minute Delger, redeemed, stops her. The Gergathan, it seems, has prepared a counter-stroke that will unleash the full power of the weapon and turn it against the Scattered Worlds. Delger helps Lirith and Jel Haran to escape, giving them valuable information that will help the Scattered Worlds defend themselves against Diebethar. Delger vows to remain and frustrate the Gergathan's plans at every turn.
Under Lirith & Jel Haran's supervision, the Mamauklans return to their own world with a population of Forcora volunteers. The Forcora can live on Mamaukl, safe beneath its oceans, while they cultivate algae and underwater animals to restore the planet's ecology. Lirith promises that they will have the help of the Scattered Worlds, and that Mamaukl will be habitable again within a few generations.
Then Lirith and Jel Haran retreat to the secret Secluded Realm, where they pledge they will continue the fight against Diebethar even if the Council of the Free Peoples and the Virgans are reluctant to act.