The Darwinian Sum — David Stroup

As war threatens to break out between civilizations, two women -- one a shipwrecked human, the other a freelance warrior of the sexually-dimorphic Makers -- close in on the kidnapped human consul at the heart of the crisis. But for Aly Castillos and A'thiathialae, finding the missing diplomat is only the start of a lethal end-game.

Meanwhile, in deep space, a young artificial intelligence named Hawkens DuPree enters into a deadly dance with terrorists and political extremists ... including her ex-lover. Each deception reveals new questions -- and a fatal rendezvous with the agents of an unseen enemy.

For freelance journalist Temple Argent and scientist Kathryn Tamashio, time may already have run out, as the trail of a killer leads only to cold death among the stars.

Across known space, humans and A.I.'s struggle to put together the pieces of a vast conspiracy before it's too late. Behind the scenes, intelligences older and far more powerful than any human or Maker brood in the cold darkness between the stars. When the Engines of Dusk make their move, two civilizations may fall, and something new will be born ... because the first move in an interstellar war may be just one step toward something far greater.