Across the desk, beneath a ring of tape where someone once taped a note, sat a worn hardcover. Its spine had been softened until the title—Analog Design Essentials—was almost a whisper. Marta remembered the first time she’d opened it: pages full of diagrams like constellations, equations that looked like spells, margins crowded with someone else’s inked marginalia. It had belonged to a man named Sansen in her mind, a voice polite and severe that taught how to hear circuits, not just build them.