Kingdom of Salt and Iron: Where Oaths are Deadly

In a world where oaths are enforced by ancient Salt Laws - and breaking one is a death sentence - Seren Ashvale should be dead. Three years ago, she broke a sacred oath to save a child from a burning building. She survived. The pale, cold wound on her wrist - the Hollow - is the proof. A mark the empire calls criminal. A mark scholars now believe contains something far more dangerous: the architectural impression of the Salt Laws themselves.
When Empress Vireth dispatches her best Oath-Warden to bring Seren in - not for trial, but for study - the empire's most reliable officer is forced to make a choice. Calder Voss has spent sixteen years delivering prisoners intact. He has never questioned a directive. He questions this one. What begins as a capture becomes an uneasy alliance, then something neither of them has a word for yet. Together, they uncover the Empress's true plan: a Sovereign Oath that would place her beyond all binding, leaving every other person in the empire permanently, legally, inescapably bound.
To stop it, they will need the oldest woman in the empire, the original documents no one has seen in centuries - and the one thing Seren has carried in her body for three years without knowing what it was. Not a wound. Not a crime. A witness.