The Snow Queen Cycle Series by Joan D. Vinge

The imperious Winter colonists have ruled the planet Tiamat for 150 years, deriving wealth from the slaughter of the sea mers. But soon the galactic stargate will close, isolating Tiamat, and the 150-year reign of the Summer primitives will begin. All is not lost if Arienrhod, the ageless, corrupt Snow Queen, can destroy destiny with an act of genocide... moreThe imperious Winter colonists have ruled the planet Tiamat for 150 years, deriving wealth from the slaughter of the sea mers. But soon the galactic stargate will close, isolating Tiamat, and the 150-year reign of the Summer primitives will begin. All is not lost if Arienrhod, the ageless, corrupt Snow Queen, can destroy destiny with an act of genocide. Arienrhod is not without competition as Moon, a young Summer-tribe sibyl, and the nemesis of the Snow Queen, battles to break a conspiracy that spans space. less

Sequel To The Hugo Award-Winning Bestseller The Snow Queen The Summer Queen is the extraordinary sequel to one of science fiction's most celebrated novels, The Snow Queen . Set in a fully realized universe of wonders, this spectacular space epic, itself a finalist for the Hugo Award, is one of the most remarkable novels in the field... moreSequel To The Hugo Award-Winning Bestseller The Snow Queen The Summer Queen is the extraordinary sequel to one of science fiction's most celebrated novels, The Snow Queen . Set in a fully realized universe of wonders, this spectacular space epic, itself a finalist for the Hugo Award, is one of the most remarkable novels in the field. A story that spans millennia, from the ruins of an ancient interstellar empire to the planets of the Hegemony that rules human space, The Summer Queen is the multi-layered story of Tiamat, a world where the dolphin-like mers are harvested for the youth-prolonging serum extracted from their blood. But Tiamat is much more, for beneath Carbuncle, its capital, lies the old empire's greatest secret: an enormous forgotten technology which, though decaying, continues to affect the fates of the fallen empire's remnant cultures via the sybil-network--a data bank that binds the past and the future in its web of knowledge, As the Smith, genius mastermind of the hidden interstellar Brotherhood, tries feverishly to unlock its secrets, BZ Gundhalinu desperately strives to save the Hegemony, while the Summer Queen herself dares to create a new future for her people and her planet. And though each is acting alone, their fates will entwine in an astonishing climax that will change the universe forever. less