His hands held Underhill’s attention. Immense hands, they hung a little forward on long bony arms in perpetual readiness. Gnarled and scarred, darkly tanned, with the small hairs on the back bleached to a golden color, they told their own epic of varied adventure, of battle perhaps, and possibly even of toil. They had been very useful hands.

“I’m very grateful to your wife, Mr. Underhill.” His voice was a deep-throated rumble, and he had a wistful smile, oddly boyish for a man so evidently old. “She rescued me from an unpleasant predicament. I’ll see that she is well paid.”

Just another vivid vagabond, Underhill decided, talking his way through life with plausible inventions. He had a little private game he played with Aurora’s tenants—he just remembered what they said, counting one point for every impossibility. Mr. Sledge, he thought, would give him an excellent score.

“Where are you from?” he asked conversationally.

Sledge hesitated for an instant before he answered, and that was unusual—most of Aurora’s tenants had been exceedingly glib.

“Wing IV.” The gaunt old man spoke with a solemn reluctance, as if he should have liked to say something else. “All my early life was spent there, but I left the planet nearly fifty years ago. I’ve been traveling, ever since.”

Startled, Underhill peered at him sharply. Wing IV, he remembered, was the home planet of those sleek new mechanicals. This old vagabond looked too seedy and impecunious to be connected with the Humanoid Institute. His brief suspicion faded. Frowning, he said casually:

“Wing IV must be rather distant?”

The old rogue hesitated again, and then said gravely:

“One hundred and nine light-years, Mr. Underhill.”

That made the first point, but Underhill concealed his satisfaction. The new space liners were pretty fast, but the velocity of light was still an absolute limit. Casually, he played for another point:

“My wife says you’re a scientist, Mr. Sledge?”

“Yes.”

The old rascal’s reticence was unusual. Most of Aurora’s tenants required very little prompting. Underhill tried again, in a breezy conversational tone:

“Used to be an engineer myself, until I dropped it to go into mechanicals.” The old vagabond straightened, and Underhill paused hopefully. But he said nothing, and Underhill went on: “Fission power-plant design and operation. What’s your specialty, Mr. Sledge?”

The old man gave him a long, troubled look, with those brooding, hollowed eyes, and then said slowly:

“Your wife has been kind to me, Mr. Underhill, when I was in desperate need. I think you are entitled to the truth, but I must ask you to keep it to yourself. I am engaged on a very important research problem, which must be finished secretly.”

“I’m sorry.” Suddenly ashamed of his cynical little game, Underhill spoke apologetically. “Forget it.”

But the old man said deliberately:

“My field is rhodomagnetics.”

“Eh?” Underhill didn’t like to confess ignorance, but he had never heard of that. “I’ve been out of the game for fifteen years,” he explained. “I’m afraid I haven’t kept up.”

The old man smiled again, faintly.

“The science was unknown here until I arrived, a few days ago,” he said. “I was able to apply for basic patents. As soon as the royalties start coming in, I’ll be wealthy again.”

Underhill had heard that before. The old rogue’s solemn reluctance had been very impressive, but he remembered that most of Aurora’s tenants had been very plausible gentry.

“So?” Underhill was staring again, somehow fascinated by those gnarled and scarred and strangely able hands. “What, exactly, is rhodomagnetics?”

He listened to the old man’s careful, deliberate answer, and started his little game again. Most of Aurora’s tenants had told some pretty wild tales, but he had never heard anything to top this.

“A universal force,” the stooped old vagabond said solemnly. “As fundamental as ferromagnetism or gravitation, though the effects are less obvious. It is keyed to the second triad of the periodic table, rhodium and ruthenium and palladium, in very much the same way that ferromagnetism is keyed to the first triad, iron and nickel and cobalt.”

Underhill remembered enough of his engineering courses to see the basic fallacy of that. Palladium was used for watch springs, he recalled, because it was completely non-magnetic. But he kept his face straight. He had no malice in his heart, and he played the little game just for his own amusement. It was secret, even from Aurora, and he always penalized himself for any show of doubt.

He said merely, “I thought the universal forces were already pretty well known.”

“The effects of rhodomagnetism are masked by nature,” the patient, rusty voice explained. “Besides, they are somewhat paradoxical, so that ordinary laboratory methods defeat themselves.”

“Paradoxical?” Underhill prompted.

“In a few days I can show you copies of my patents, reprints of papers describing demonstration experiments,” the old man promised gravely. “The velocity of propagation is infinite. The effects vary inversely with the first power of the distance, not with the square of the distance. And ordinary matter, except for the elements of the rhodium triad, is generally transparent to rhodomagnetic radiations.”

That made four more points for the game. Underhill felt a little glow of gratitude to Aurora for discovering so remarkable a specimen.

“Rhodomagnetism was first discovered through a mathematical investigation of the atom,” the old romancer went serenely on, suspecting nothing. “A rhodomagnetic component was proved essential to maintain the delicate equilibrium of the nuclear forces. Consequently, rhodomagnetic waves tuned to atomic frequencies may be used to upset that equilibrium and produce nuclear instability. Thus most heavy atoms—generally those above palladium, 46 in atomic number—can be subjected to artificial fission.”

Underhill scored himself another point, and tried to keep his eyebrows from lifting. He said only:

“Patents on such a discovery ought to be profitable.”

The old scoundrel nodded his gaunt, dramatic head.

“You can see the obvious applications. My basic patents cover most of them. Devices of instantaneous interplanetary and interstellar communication. Long-range wireless power transmission. A rhodomagnetic inflexion-drive, which makes possible apparent speeds many times that of light—by means of a rhodomagnetic deformation of the continuum. And, of course, revolutionary types of fission power plants, using any heavy element for fuel.”

Preposterous! Underhill tried hard to keep his face straight, but everybody knew that the velocity of light was a physical limit. On the human side, the owner of any such remarkable patents would hardly be begging for shelter in a shabby garage apartment. He noticed a pale circle around the old vagabond’s gaunt and hairy wrist; no man owning such priceless secrets would have to pawn his watch.

Triumphantly, Underhill allowed himself four more points, but then he had to penalize himself. He must have let doubt show on his face, because the old man asked suddenly:

“Do you want to see the basic tensors?” He reached in his pocket for pencil and notebook. “I’ll jot them down for you.”

“Never mind,” Underhill protested. “I’m afraid my math is a little rusty.”

“But you think it strange that the holder of such revolutionary patents should find himself in need?”

Nodding uncomfortably, Underhill penalized himself another point. The old man might be a monumental liar, but he was shrewd enough.

“You see, I’m sort of a refugee,” he explained apologetically. “I arrived on this planet only a few days ago. I have to travel light. I was forced to deposit everything I had with a law firm, to arrange for the publication and protection of my patents. I expect to be receiving the first royalties soon.

“In the meantime,” he added plausibly, “I came to Two Rivers because it is quiet and secluded, far from the spaceports. I’m working on another project which must be finished secretly. Now will you please respect my confidence, Mr. Underhill?”

Underhill had to say he would. Aurora came back with the freshly scrubbed children, and they went in to dinner. The android came lurching in with a steaming tureen. The old stranger seemed to shrink from the mechanical, uneasily. As she took the dish and served the soup, Aurora inquired lightly:

“Why doesn’t your company bring out a better mechanical, dear? One smart enough to be a really perfect waiter, warranted not to splash the soup. Wouldn’t that be splendid?”

Her question cast Underhill into moody silence. He sat scowling at his plate, thinking of these remarkable new mechanicals which claimed to be perfect, thinking of what they might do to the agency. It was the shaggy old rover who answered solemnly:

“The perfect mechanicals already exist, Mrs. Underhill.” His rusty voice had a solemn undertone. “And they are not so splendid, really. I’ve been a refugee from them, for nearly fifty years.”