Katherine Lundy is eight years old, the serious middle child of a school principal, and far more at home among books and rules than among the other children who never quite know what to make of her. Then, one day, she finds a door marked "Be Sure" and walks through it into the Goblin Market — a strange, wonderful world governed by a single unbreakable principle: fair value. Nothing is given for free; every debt, favor, and cruelty must be repaid in kind, or the Market itself begins to collect.
For Lundy, the Market is paradise: a place of logic and honesty and a fierce best friend named Moon, where she is finally, wholly at home. But the door does not stay open forever, and the rules that make the Market so perfect also make it unforgiving. As Lundy crosses back and forth between two worlds and the years press on, she is forced toward a choice, and a bargain, of the kind that never plays out well.
The fourth Wayward Children novella is a quietly devastating fairy tale about belonging, the cost of the things we want, and the impossibility of being fully at home in more than one world.