The fluorescent hum of room 214 woke him the way a scalpel wakes a patient—slow, precise, then entirely too bright. Eric opened his eyes to graph paper angles and the shout of a teacher trying to be heard over teenage breath. His mouth tasted like copper and stale coffee. He sat up, half-disoriented, aware of the rhythm at his wrist like a second heart. “Eric Han—answer the problem,” Mr. Turner said, chalk screeching across the board. His voice had that tired, late-summer friction schools get. Seventeen faces turned. A phone screen lit with a meme. Somewhere, someone laughed too loud. Eric's hand went up before he could think. It was an old reflex. Operating theater drills that he had run a thousand times in a life that felt like a different skin snapped into place: read the lines, find the leverage, trust spatial memory. His palm tingled. The watch under his sleeve thumped in time, small but urgent. He stood. “DE equals four,” he said before his throat could close. The words were soft and precise, surgically neat. A chorus of snorts, then silence. Mr. Turner lowered his marker, eyebrows an inch higher than usual. “Explain.” He moved to the board like someone sent him a private instruction. The class watched the lines on the board like they'd been given front-row seats to a trick. Eric's marker wrote without thought—angles, parallel lines, a pair of triangles that matched up like bones. He