He phoned the plant and requisitioned transistors, metal film resistors, capacitors, and various other components necessary for his task. Handworthy did not approach him as he worked and his meals were served to him either in his own room or the great room where all the automata were located. He made all the changes himself, snipping leads, soldering, forming tight mechanical joints with deft fingers that almost seemed alive and apart from his body.
Ten days later, he called in Amos Handworthy and demonstrated what he had done.
"I've modified both guns so that you and the Marshal will now shoot at each other with ultra violet light. You'll both wear vests that are sensitive to this light. I monitor the hits electrically by measuring the resistance of those areas where a bullet would severely injure a man. Nothing will occur unless you or the Marshal are hit in such an area. Furthermore, you can both continue to shoot for an indefinite length of time. However, I've altered the Marshal's aiming mechanism so that if he's hit in a vital spot, he won't shoot as accurately. Similarly, if you are hit, a defocussing mechanism operates on your light bulb so that your gun is no longer as accurate. And instead of the recorded voice, if either of you is hit in the heart, your gun goes dead."
Amos Handworthy's eyes began to glow with a fire such as Manny Steinberg had never seen and it excited him that his work had brought on so wonderful a response. He slipped the new vest on Handworthy, handed him the wired holster and gun, and stepped back. After fastening his belt and readying himself, Handworthy drew as before and fired swiftly at the Marshal, who was firing back almost as rapidly. Suddenly Handworthy stopped and looked at his gun in dismay.
"My trigger's locked," he cried.
"He's killed you," said Manny drily. "You beat him to the draw, but he's hit you in the heart."
"I see," said Handworthy slowly. "Then it looks like I've got a hell of a lot more practicing to do."
It was a full month before Manny Steinberg was invited back to the Mansion, and with great pride his host demonstrated how he killed the Marshal, every time.