Powell repressed a sudden attack of nerves. These robots possessed peculiar brains. Oh, the three Laws of Robotics held. They had to. All of U.S. Robots, from Robertson himself to the new floor-sweeper, would insist on that. So QT-1 was safe ! And yet—the QT models were the first of their kind, and this was the first of the QT’s. Mathematical squiggles on paper were not always the most comforting protection against robotic fact.