Though he didn't think he was particularly attached to his little prison cell away from home, the sight of an uninvited guest sent a panic through Tony that he hadn't anticipated and that wasn't quelled fast enough by the instant recognition of the intruder. There were boundaries that Tony was used to having, and took for granted, he was realizing, when he couldn't seal everyone out of his personal bubble to concentrate. Instead, he had people letting themselves in, getting too close to him and cutting him deep. So he was ready to snap at Pietro for the intrusion and send him away with a swift kick in the ass when he saw Pietro's hands-- or, not quite his hands but the blur of them, so fast but so rhythmical he could have been a robot on an assembly line. Tony stopped, mouth open at the door of the cell, watching Pietro move down his neat rows with such hypnotized intent that he hardly realized what Pietro was doing until he stopped.
Tony wasn't looking at him when he turned, studying instead the array of tools, okay, they could have been from anywhere, then the progressive familiarity of the dented chassis, cracked circuit board and the warped arm with the unmistakable DUM-E printed on the side. "Why are you doing this?" Tony breathed, still taking stock of the array, counting screws and searching for gears. It wasn't as though Tony had shown Pietro anything more than civil kindness since he arrived, and this was just a fucking machine Pietro had to be risking his neck for. He couldn't know how much it hurt to see it mangled and fractured, lain out carefully like a wake, grabbing Tony by the collar and reminding him only the weak and cowards cried and everything died. It was cruel. It was just a fucking machine.