As an officer of the Special Patrol Service, it has often been my duty to show parties and individuals through my ship. Most of these parties are composed of females, who have only exclamations to make instead of intelligent comment, and who possess an unbounded capacity for asking utterly asinine questions. It was, therefore, a real pleasure to show Harbauer through the ship. He was a keen, eager listener. When he asked a question, and he asked many of them, he showed an amazing grasp of the principles involved. My knowledge of our equipment was, of course, only practical, save for the rudimentary theoretical knowledge that everyone has of present-day inventions and devices. The ethon tubes which lighted the ship, interested him but little. The atomic generators, the gravity pads, their generators, and the disintegrator-ray, however, he delved into with that frenzied ardor of which only a scientist, I believe, is capable. Questions poured out of him, and I answered them as best I could: sometimes completely, and satisfactorily, so that he nodded and said, "I see! I see!" and sometimes so poorly that he frowned, and cross-questioned me insistently until he obtained the desired information. In the big, sound-proof navigating room, I explained the operation of the numerous instruments, including the two three-dimensional charts, actuated by super-radio reflexes, the television disc, the attraction meter, the surface-temperature gauge and the complex control system. "Forward," I added, "is the operating room. You can see it through these glass partitions. The navigating officer in command relays his orders to men in the operating room, who attend to the actual execution of those orders." "Just as a pilot, or the navigating officer of a ship of my day gives his orders to the quartermaster at the wheel," nodded Harbauer, and began firing questions at me again, going over the ground we had covered, to check up on his information. I was amazed at the uncanny accuracy with which he had grasped such a great mass of technical detail. It had taken me years of study to pick up what he had taken from me, and apparently retained intact, in something more than an hour, Earth time. * * * * * I glanced at the Earth-time clock on the wall of the navigating room as he triumphantly finished his questioning. Less than an hour remained before the time set for our return trip. "I'm sorry," I commented, "to be an ungracious host, but I am wondering what your plans may be? You see, we are due to start in less than an hour, and--" "A passenger would be in your way?" Harbauer smiled as he uttered the words, but there was a gleam in his long eyes that rather startled me, and I wondered if I only imagined the steeliness of his voice. "Don't let that worry you, sir."