The tournament registration queue was two hundred metres long and smelled like anxiety and fried dough.

  Chen Xi stood in it because Wu Zheng had insisted, and Wu Zheng had insisted because Wu Zheng, for all his seventy-three years of graveyard-forged cynicism, harboured a streak of competitive spite that the Silted Bones had pickled rather than killed.

  "Enter the tournament," he had said over breakfast — a congee made from rice he'd bartered for with spirit stones, seasoned with something green he'd found growing in the cracks of their inn's courtyard wall and which tasted, impossibly, of lemongrass and warm earth.

  "Enter it, win it, and make the Azure Dust Sect watch."

  So here he was, standing behind a woman carrying a spear twice her height and ahead of a boy who would not stop talking.

  The boy was perhaps fifteen.

  Thin in the way of people who had grown upward without their bodies' permission, all elbows and neck, wearing robes that had been let out at the hem twice and were contemplating a third extension.

  His hair was pulled into a topknot that listed thirty degrees to port. He carried no weapon and appeared to be vibrating.

  "First tournament?" the boy asked, for what Chen Xi estimated was the fourth time, having received no response to the first three.

  "Yes."

  "Me too. Well, third. But first time I'm actually competing. First two times I was selling roasted chestnuts in the spectator section.

  Did you know there's a direct correlation between the length of a match and chestnut sales? Short matches, low sales. People don't have time to get hungry. Long matches, huge sales.

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  My best day was when two Core Formation elders fought for forty minutes and I sold three hundred bags.

  I keep records."

  Chen Xi, who had been actively ignoring this monologue, stopped ignoring it. "You keep records."

  "Of everything. Chestnut sales, match durations, technique frequencies, audience reactions, weather patterns, sword types—"

  The boy produced, from somewhere in his voluminous robes, a notebook. It was thick, battered, and bristling with markers made from torn cloth.

  "I've been tracking Sword Conference data for three years. Want to see my analysis of Azure Dust Sect match outcomes relative to phase of moon?"

  "You track data."

  "Obsessively. My mother says it's a disorder. My master says I'm unteachable.

  But the numbers don't lie, and the numbers say that Azure Dust Sect fighters win fourteen percent more matches during waning moons, which is either a statistical fluke or they've got a cultivation technique that's lunar-dependent, and I've been trying to figure out which for—"

  "What's your name?"

  "Shen Wei. But everyone calls me Little Abacus."

  "Why?"

  "Because I count things."

  Chen Xi looked at this boy — this skinny, vibrating, data-obsessed chestnut vendor — and felt something he had not expected to feel in a sword tournament registration queue: recognition.

  "Little Abacus," he said. "Would you like to see something interesting?"

  "Always."

  "After we register, meet me at the Arena's eastern monitoring station. I'll show you what the formation sensors are actually measuring."

  Little Abacus's eyes went wide. It was the face of a boy who had just been invited into a world he'd been pressing his nose against the glass of for three years.

  "I'll bring chestnuts," he said.

  ---

  Su Yiran found them an hour later — Chen Xi explaining energy flux equations using a stick in the dirt while Little Abacus sat cross-legged taking notes so fast his brush was a blur, a bag of roasted chestnuts cooling between them — and her expression cycled through confusion, amusement, and something that might have been tenderness before settling on professional interest.

  "You've adopted a student," she said.

  "I've acquired a data collection asset. He has three years of Sword Conference statistics in that notebook."

  "I have six years," she said. "But I store mine on tablets like a professional."

  "Can yours cross-reference match duration with chestnut sales?" Little Abacus asked, without looking up.

  Su Yiran paused. "No."

  "Then mine are better."