Ludo Crane wanted a library where every broken person could find the book that healed them. She had the room for it, hidden above her shop, up a narrow stair. She had the shelves too. Tonight she stood before them and counted only nine books left. Nine books cannot mend a town. A library with empty shelves is just a promise nobody keeps. She ran a long finger along the bare wood. Her back ached from years of bending under low doorways. The rare books she needed were gone, sold or lost. The mending kind, the ones that found the exact wound in a reader, could not be bought at any market. Without them her stairs led nowhere. A bell rang below. Ludo ducked through the doorway and went down. A young swordsman stood in her shop. He wore a silver breastplate, dented and stained. Dark curls hung over hard eyes. He laughed at nothing, too loud, and the sound had no warmth in it. Ludo saw why. Beneath the breastplate his chest was hollow. Something had carved his heart out and left the space empty. "They told me you find the right book for a person," he said. "I doubt it. But I have coin." He set a glass cat on her counter. It was clear as ice, sleek, and cold to look at. One yellow eye caught the lamplight. "This is worth more than any book," he said. "Payment. If you can find one that fits a man like me." Ludo lifted the glass cat. It weighed almost nothing. Its hollow body made her think of his hollow chest. She set it down gently. "I keep no book for you yet," she said, low and slow. "My shelves are near bare. But I know where mending books hide." The swordsman leaned close. "Then trade with me. I go north, three days, hunting the man who cut me. His house holds old books. Rare ones. He collects them." Ludo's heart quickened. Rare books. The exact thing her shelves starved for. "Bring me his books," she said, "and I will read you until I find the one that fits." He grinned and slid the glass cat toward her. "Keep this until I return. If I don't, it's yours." Then he was gone into the dark. Ludo carried the glass cat up her narrow stair. She placed it on the empty shelf, alone. It watched her with its one yellow eye. The shelves were still bare, but now they had a promise pinned to them. To fill her library, she had tied its fate to a heartless man walking three days north toward the person who unmade him. If he died, her shelves stayed empty. If he lived, she owed her books to blood.