Forge of Heaven is a science fiction novel by American science fiction and fantasy author . It was first published in June 2004 in the United States by HarperCollins under its Eos Books imprint. Forge of Heaven is the second of two novels set in Cherryh's Gene Wars universe, and concerns gene manipulation using nanotechnology, and contact with an alien race, the ondat. The first novel, Hammerfall was published in June 2001. Backstory Human territory consisted of the Inner Worlds, governed by Earth Federation, who maintained strict control on the use of biotech and frowned on genetic manipulation, and Outsider Space, near the edge of human space, who openly used biotech for their own benefit. In Outsider Space a group called the Movement broke away from local authority, and by joining nanotech and biotech, bioengineered humans, livestock and agriculture for the colonizing other planets. Fearing contamination, Earth severed all direct contact with Outsider Space, but assisted the moderate Outsider governments, who themselves feared runaway biochange, in tracking down and destroying Movement bases. The outlawed Movement moved their biotech beyond Outsider Space and onto worlds, unbeknown to them, in space occupied by an unknown alien species, the ondat. The ondat came into contact with the Movement's aggressively adaptive nanisms and unwittingly spread it to their homeworld. Unable to distinguish between the Movement, Outsiders and Earth, the aliens went to war with humankind, sparking the Gene Wars. But when they saw Earth and the Outsiders destroying Movement bases, the ondat learnt that not all humans were the enemy. After the Movement was neutralized, the ondat withdrew to their original borders, and Earth and the Outsiders maintained a shaky truce with the ondat that lasted for 300 years. Second and Third Movements later sprang up, but they were driven underground and eventually eliminated. The ondat were an enigma: no one ever saw them and communication was all but impossible. But years after the end of the Gene Wars, an ondat ship initiated contact by entering human space and leading a human ship to a planet in ondat territory that had a functioning First Movement base. They indicated that they wanted to destroy the world, and Earth concurred, but the Outsiders wanted to rescue those on the planet and get their hands on First Movement technology that may have advanced beyond what they had previously encountered. Earth yielded to the Outsider's request because they