In a corporate-dominated spacefaring future, planetary missions must be approved and supplied by the Company. Exploratory teams are accompanied by Company-supplied security androids, for their own safety. But in a society where contracts are awarded to the lowest bidder, safety isn’t a primary concern. On a distant planet, a team of scientists are conducting surface tests, shadowed by their Company-supplied ‘droid—a self-aware SecUnit that has hacked its own governor module, and refers to itself (though never out loud) as “Murderbot.”

Within the Eastern Empire, Duke Kordas Valdemar rules a tiny, bucolic Duchy that focuses mostly on horse breeding. Anticipating the day when the Empire's exploitative and militant leaders would not be content to leave them alone, Korda's father set out to gather magicians in the hopes of one day finding a way to escape and protect the people of the Duchy from tyranny.

With a ragged peace in place, demons burn farmlands, violent Reivers roam the wilds and plague has spread beyond the Black Meadows. The country is on its knees. In a society that fears and shuns him, Aranok is the first magically-skilled draoidh to be named King's Envoy. Now, charged with restoring an exiled foreign queen to her throne, he leads a group of strangers across the ravaged country. But at every step, a new mystery complicates their mission.

Something is amiss with the world's magic. Spells don't work the way they used to—when they work at all. Only the powers of the Crystal Mages remain as they were, powers founded on the use of the mystical element adamis, the harvesting of which has enslaved the peoples of the Twilight Lands. Ravenous beasts have begun to appear, legendary creatures that seem to be proof against any magic.

Avery is an exceptional child. Everything he does is precise, from the way he washes his face in the morning to the way he completes his homework - without complaint, without fuss, without prompt. Zib is also an exceptional child, because all children are, in their own way. But where everything Avery does and is can be measured, nothing Zib does can possibly be predicted, except for the fact that she can always be relied upon to be unpredictable. They live on the same street. They live in different worlds.