Once a year, Tyrac asks Leila to marry him.Once a year, she answers, "No."She has no choice. She and Tyrac are Kin, and the Kin have rules.Rules written by the gods themselves.As a priestess, Leila has dedicated her entire life to the reclusive Kin and the forgotten gods they worship. Even if it means enforcing their brutal dictates. Even if it means she can't be with the man she loves. Despite his fractured faith in the gods, there's little Tyrac won't do for Leila. But after years of compliance for Leila's sake, Tyrac finds himself unable to turn a blind eye to her violent deeds.

As their relationship crumbles, the two are selected to undertake a quest few have taken, and even fewer have survived. They must leave the safety of their home and travel across the treacherous expanse of Andos in search of a hidden, underground city in a far-off realm. Along with an elegant warrior princess, a temple librarian, a newly converted outsider, and two bratty teenagers, Leila and Tyrac find themselves far from home and pursued across unfamiliar land by ex-Kin intent on subverting their mission at any cost.

The journey will test Leila and Tyrac like never before, forcing them to confront the countless dangers of the outside world, the truth of the Kin, and the devastating reality of how far they are willing to go for what they believe, and for each other.