Cragin knew he would not forget the look etched in the thin white lines of her face as she was led into the testing place; there was something in it that he had never seen before in the face of an Earthman. Not an expression caused purely by reflex in time of danger or pain; not one carefully controlled after finding an unpleasant solution to an inescapable problem. Neither of those. But what others.... Cragin looked then to what he might be more successful in understanding. The testing place which had been readied for him was a small, independent laboratory, much like the control room of the machine-planet, save for the complete absence of telescreens. And awaiting him were two cloaked figures in red mail--technicians, second grade. The Owners were taking no chances. He lay at full length on a sheet of metal that was as comfortably resilient and warm as an old-fashioned bed of feathers, and waited expectantly. "Are you prepared, Earthman?" "Fire away, braintrust." He wondered at the absence of equipment. Nothing was attached to him--no electrodes, none of the usual electroencephalographic devices. There was only a low hum, and the pale glow from the indistinct walls about him. "The test begins, Earthman. Display your mind as you see fit." The hum deepened. The walls became more indistinct, and the glow somehow became a part of the sound that filled the tiny chamber. Cragin flashed his mind to his first years of schooling. He had been 10 years old, had learned the square of the hypotenuse is equal to the sum of the squares of the two opposite sides ... "i" represents the square root of the quantity minus one, and is termed an imaginary number ... for every action, there is an opposite and equal reaction.... He lost all sense of time, and guarded against thinking of it, lest he betray even a basic knowledge of continuum dynamics. Had to keep it simple, child-like, simple.... The intensity of light diminishes inversely as the distance from its source is squared. The voice inside his head was at length the signal that the test was completed. "From this examination, Earthman, it is evident that you stumbled where you did purely by accident, and that the craft in which you traveled was out of control, operating entirely beyond your understanding." Cragin kept his thoughts diffuse and made no effort to reply. "Do I serve or die?" he asked at length. "On a probationary basis, you serve. Grade, twelfth." The test was done, and Cragin had won the first cast of the dice.