The invention of faster-than-light technology has brought great opportunity, but also great danger. The Black Horizon conspiracy is broken up, but it still has deadly assets beyond the reach of Earth. As the great powers jostle for advantage, the alien minds known as the Fermi have their own ways of dealing with humans meddling in plans vaster and more ancient than anyone can suspect. After the Venus catastrophe, John Grant’s starship Fighting Chance and the Space Station have reached Apis --- but not for long. They barely have time to mourn the dead before they’re chased out of the system. The Station begins exploring the systems that Black Horizon warned them against --- with good reason, as they soon discover.

Mathematician Lakshmi Nayak receives a letter from her future self about faster-than-light travel. The equations work, and the letter itself seems to prove the possibility will be realized someday. But her paper on the topic is fiercely criticized. After defecting to the Union, she gets an unexpected offer: “I can build your ship.” Shipbuilder John Grant learns of a secret project that, unknown to the world, has been traveling to the stars for decades: Black Horizon. Biologist Emma Hazeldene works for Black Horizon on an alien world, Apis, investigating rock formations that are thought to be an alien, crystal-like intelligence. But refugees exiled to a hard life in the wilds of Apis already know more than the scientists have ever suspected. Everything changes when the rocks wake up, with dire results.