The growing threat of the dimension-invading Weird has driven the Expansion government to outright paranoia. Mandatory telepathic testing is introduced, and the colony Braun's World—following reports of a new Weird portal opening—is destroyed from orbit, at an unimaginable cost in lives.

Delia Walker, a senior analyst in the Expansion's intelligence bureau and a holdout of the pragmatic old guard, protests the oppressive new policies and is drummed out. Sure there's a better way, she charters the decrepit freighter the Baba Yaga and heads into the lawless "Satan's Reach," following rumours of a world where humans and the Weird live peacefully side by side.

Hunted by the Bureau, Walker, her pilot Yershov, and Failt—a Vetch child stowaway, fleeing slavery—will uncover secrets about both the Weird and the Expansion; secrets that could prevent catastrophic war...