Billie Tarn has made a career of finding hidden places and putting them on the map. But when she follows a forbidden mountain track, she stumbles into the Vael, a forgotten realm with no sun, where every spark of warmth and light is paid for with stolen years.

Then, she signs the wrong ledger.

One careless signature binds her as consort to Aldous Vane, the realm's grim, scarred cattle-lord, for a single season, payable in daylight drawn from her own life. And as an impossible attraction grows between them, Billie discovers a terrible truth: the road that led her into the Vael came from her own guidebook.