Return to the Seven Suns universe a terrifying celestial discovery threatens the future for humanity and the Ildirans in this space opera trilogy opener.   “Anderson hits it out of the galaxy again: space opera doesn’t get much more exciting, or much more richly populated with alien races, technologies, and cultures, than it does in this sprawling, engrossing epic.” —Booklist (starred review)   Hugo Award Nominee   Two decades after the end of the horrific Hydrogue War, a group of independent clans, the Roamers, operate giant floating skymines in the clouds of gas-giant planets, where they harvest stardrive fuel at great risk, and great profit.   On the planet Theroc, capital of the vast Confederation, humans live inside a gigantic worldforest whose towering trees are all interconnected in a single mind, which telepathic “green priests” can use for interstellar communication.   The stagnant alien Ildiran Empire once ruled the entire Spiral Arm, but they are unprepared for human politics and ambitions.   Upon this galactic canvas, a large expeditionary ship goes off to explore farther than any human or Ildiran has ever ventured. Beyond the edge of the Spiral Arm, they encounter a mysterious and ominous dark nebula, a huge black cloud so opaque that even starlight cannot penetrate it. The explorers are horrified when the dark nebula begins to expand exponentially.   The races of the Spiral Arm will be faced with an evil so ancient that knowledge of its very existence has been obliterated, but it will threaten all life, all planets, and even the fabric of the universe itself.   “A space opera to rival the best the field has ever seen.” —Science Fiction Chronicle