“No.” Leo stood up. “We redesign the joint.”

“It’s not the metal,” he said softly.

Leo was already pulling on his safety glasses. He didn’t walk to the line. He drifted. In his mind, he was already inside the failure.

Daria watched the second cycle. Then the tenth. Then the hundredth.

Three hours later, after the janitor had swept around him twice, Leo finished the model. He sent it to the additive manufacturing lab across the street. By 10 PM, the new sleeve was printed in D2 tool steel, still warm.