Elijah worked at that table with Marcus and Amara. They challenged visitors to color a small pattern, then repeated the pattern across connected sheets of paper to show how a choice that looked harmless could fail at a distant seam. Adults found themselves arguing about blue and green squares with the seriousness of researchers, then laughing when a child pointed out the rule they had overlooked. Elijah enjoyed the conversations because he no longer had to defend his right to ask the question. He only had to explain it clearly enough for somebody else to join him.
An elderly man wearing a maintenance-company jacket stopped beside the display and studied the drawings for several minutes. He said he had worked in warehouses all his life and could never understand why children spent so much time on abstract mathematics. Elijah asked how the man organized shelves when shipments came in different sizes and had to fit within fire-safety rules. The man began describing the problem, drawing rectangles on a scrap of paper. Soon they were discussing constraints, packing, and why a solution that fit one arrangement might fail when a doorway moved.
"So this is mathematics?" the man asked, looking at his own drawing.
"Yes, sir," Elijah said. "Maybe not the same mathematics I was doing, but it's still thinking about rules and patterns. You already know a lot about it."
The man laughed in astonishment. "Nobody ever told me that before." He shook Elijah's hand and spent another twenty minutes teaching children how a real warehouse floor differed from a clean diagram. Okonkwo watched from a distance, pleased by the exchange. She had hoped the festival would make expertise visible in both directions, showing that a research professor and a maintenance worker might each understand something the other needed to learn.
Late in the afternoon, Whitfield appeared quietly at the festival. He had notified Okonkwo of his intention to attend, and she had agreed on the condition that he come as a visitor, not as a featured celebrity. He wore a dark sweater instead of a suit and stood near the back while children demonstrated their projects. Several adults recognized him from the symposium footage, and a few watched with suspicion. Whitfield did not attempt to turn their attention toward himself.
Elijah spotted him while putting away markers. For a moment he felt the old tightening in his chest, followed by an unexpected calm. He walked over and asked whether the professor wanted to see Amara's bridge experiment. Whitfield agreed, and they spent half an hour listening while Amara described the designs that had collapsed before she found one that worked. He asked a question about how she measured the load and waited through her long explanation without interrupting.
Afterward Whitfield told Elijah that Amara was a promising problem solver. Elijah smiled. "I know," he answered. "She sees things I miss."
The professor looked across the hall, where children were rearranging chairs for a group photograph. "I suspect everyone in this room sees something I miss," he said. It was not a sentence that repaired the past, but it was one Elijah would remember.