Young Rimon Farris is a Sime with a happy home life, heir to his father's prosperous and famous Genfarm, a sweetheart growing up beside him, his life of privelege and power mapped out peacefully before him.  

Then his sweetheart reaches physical maturity, and as so many children of Simes do, Establishes - becomes a Gen, an animal to be Killed for selyn.  

Rimon has a decision to make, and for him it's a no-brainer, even though his need to Kill a Gen is upon him, hard, urgent, and days early.  

He helps his Gen sweetheart run for the border of Sime Territory, an illegal act in itself.  But at the border, she can flee into Gen Territory and have a chance at a normal life instead of a quick death or use as a breeder of Gens.  

But things are not that simple.  For Rimon Farris they will never be that simple.  

From the moment when his Need overwhelms him and he Kills his sweetheart and she survives the experience eager to do it again, he has to face the fact that he's "different" - and with that difference come obligations to all humanity.  

The problem: Rimon Farris has no idea what it is about him that's different - if anything.  

Zeth Farris, son of Rimon Farris, is growing up sheltered in the frontier settlement called Fort Freedom, where they are still trying to puzzle out how Channeling works and how a community of Simes and Gens can survive together.  

Zeth is firmly convinced he'll never Kill if he Changes Over.  He has vowed it.  

Zeth is the first child born of one Sime and one Gen parent to be raised as a human being, a portentious beginning to a life with a Destiny.  Expectations and hope lie heavy upon his young shoulders even though nobody knows if he'll be Sime or Gen.    

And so, when Raiders threaten his community, even though he's still a child, still not a Sime or a Gen, Zeth Farris takes matters into his own hands -- quite naturally for a boy being trained to be a leader.  

Zeth saddles up and rides for the Gen settlement just over the Gen Territory border, prepared to beg the town where the Gen children of Fort Freedom have sought refuge for the help that Fort Freedom must have to survive, and to continue to take in the Sime children of that nearby settlement.  As a child, he should be safe.  

But life is not to be that simple for Zeth, as it was not for his father.  His Changeover overwhelms him while on the trail to the Gen settlement - and he is stricken while among Gens.  

Will he keep his vow?