In deep space, a young artificial intelligence named Hawkens DuPree is fighting for her life, pursued by the agents of an unknown enemy. Run to ground in a law station, she joins with an unlikely ally to follow the clues -- but will the truth hit too close to home? Meanwhile, on the edge of human civilization, freelance journalist Temple Argent and scientist Kathryn Tamashio lay a trap for a murderer. En route from a planet-wide laboratory to a rugged frontier world, they find themselves fighting for their lives. And deep within the territory of the alien Makers -- an advanced, sexually dimorphic civilization that was at war with humanity a generation ago -- a shipwrecked human pilot and an alien hired gun join forces to rescue a kidnapped consul.
But as Aly Castillos and A’thiathialae grow closer, the man they seek becomes a pawn in a conspiracy that could shake two civilizations to their roots. The drumbeat of war builds, and a handful of humans, aliens, and artitificial intelligences race against time ... but as the Engines of Dusk move new pieces onto the board of their deadly game, it may already be too late.