Adam and Brute followed Goat Hennessey down the corridor, towering over him like Saint Bernards on the heels of a terrier. They turned into the dining room, a big square room centered with a rude table and chairs, one wall pierced by a fireplace in which a big cauldron steamed over smouldering coals.

The dining room swarmed with a dozen small creatures, human in their pink flesh, more or less human in their twisted bodies. As soon as Goat entered with Adam and Brute in tow, the assemblage set up a high-pitched howling and twittering of anticipation and began beating utensils on the dishes, table and walls.

"Quiet!" squawked Goat over the tremendous clatter, and the noise subsided. They stood where they were, bright eyes fixed on him.

These were "the children." Some of them were humpbacked, like Evan, the one who had carried the message to the tower. Some, like Evan, were grotesquely barrel-chested, with or without the hump. Some were as thin as skeletons, with huge heads; some were hulking miniatures of Brute. One steatopygean girl was so bulky in legs and hindquarters that she could waddle only a few inches with each step, yet her head and upper torso were skinny and fragile.

Goat sat down at the head of the table, and immediately there was a tumbling rush for places. Most of the children sat, chattering, while two of the larger girls moved around the table, taking bowls to the cauldron, filling them with a brownish stew and returning them.

They ate in silence. When supper was ended, the children scattered, some to play, others to chores. Goat beckoned to Adam and Brute to follow him. He led them down the corridor and into his study.

Goat turned on the light, revealing a book-lined, paper-stacked room focused on a huge desk. He removed his marsuit to stand in baggy trousers and loose tunic. Adam and Brute stood near the door, shifting uncomfortably, for the study was normally forbidden ground.

Goat stood by a thick double window, looking out over the desert to the west. The small sun disappeared beneath the horizon even as he looked, leaving the fast-darkening sky a dull, faint red. Almost as though released by the sunset, pale Phobos popped above the horizon and began to climb its eastward way. The desert already was dark, but a stirring above it bespoke a distant sandstorm.

Goat turned from the window and faced the pair.

"Well," he snapped harshly, "what happened?"

Adam smiled confidently.

"We did as you said, father," he answered. "We walked to the edge of the canal, and we walked back. We had no water and we had no air. We did not feel tired. We did not feel sick."

"Fine! Fine!" murmured Goat.

"Father ..." said Brute.

Goat turned his eyes to Brute, and savage irritation swept over him. With that word, at that moment, Brute gave him a feeling of guilty foreboding.

"Don't call me 'father!'" snapped Goat angrily.

"But you say call you father," protested Brute, the puzzled frown wrinkling his brow. "What I call you if I not call you father?"

"Don't call me anything. Say 'sir.' What did you want to say?"

"Father, sir," began Brute again, "Adam forget. Adam fall."

With a muted roar, Adam swept his powerful arm in a backhanded arc that caught Brute full on the side of his head. The blow would have felled an ox, but Brute was not shaken. Apparently unhurt, he stood patiently, his blue eyes on Goat with something of pleading in them.

"Adam, let him alone!" commanded Goat sharply. "Brute, what do you mean, Adam fell?"

"We come back. We not far from canal. Adam fall. Adam sick. Adam turn blue."

"It is lies, father!" exclaimed Adam, glaring at Brute. "It is not true."

"Let him finish," instructed Goat. "I'll decide whether it's true. What did you do, Brute?"

"I find cactus, father," answered Brute. "I make hole in cactus. I put Adam inside. I put hole back. Adam stay in cactus. Then Adam break cactus and come out again. We come back."

Goat cogitated. If Adam had shown, symptoms of oxygen starvation.... The big canal cacti were hollow, and in their interiors they maintained reserves of oxygen for their own use. More than once, such a cactus had saved a Martian traveler's life when his oxygen supply ran short.

He turned to Adam.

"Well, Adam?" he asked.

"I tell you, father, it is lies! I do not fall. Brute does not put me in the cactus."

"And why should he lie?" asked Goat blandly.

This stumped Adam for a minute. Then he brightened.

"Brute wants to be bigger and stronger than Adam," he said. "Brute knows Adam is bigger and stronger than Brute, Brute does not like this. He tells you lies so you will think Brute is bigger and stronger than Adam."

"I know you are bigger brother, Adam," objected Brute, almost plaintively. "I not try to be bigger. Why you say you do not fall?"

"I do not fall!" howled Adam. "I do not fall, you stupid Brute!"

Goat held up a stern hand, enforcing silence.

"I can't certainly settle this disagreement, but I'd be inclined to accept what Brute says," said Goat thoughtfully. "You're smart enough to lie, Adam. Brute isn't. The only thing I can do is to run the experiment over. You shall go out again tomorrow, and this time I'll go with you."

"You'll see, father," said Adam confidently. "Adam will not fall."

"Perhaps not. But I must be sure. As much as I prefer your more human characteristics, Adam, it's entirely possible that Brute has some survival qualities that you lack."

"Is true, father," said Brute eagerly. "Some things kill Adam, they not kill Brute."

"You lie!" cried Adam again, turning on him. "Why do you lie, Brute?"

"No lie," insisted Brute. "You know, is true."

"Lie! Lie!" shouted Adam. "Adam is bigger and stronger! What do you say can kill Adam that does not kill Brute?"

"This," replied Brute calmly.

With an unhurried lunge, he picked up a heavy knife from Goat's desk. In a single easy movement, he turned and slashed Adam's throat neatly.

Choking and gurgling, Adam sank to his knees, bright blood spouting from his neck, while Goat stood frozen in horror. Adam fell prone, he kicked and threshed convulsively like a beheaded chicken, then twitched and lay still in a spreading pool of blood.

Brute calmly wiped the knife on his naked thigh and laid it back on the desk.

"Adam dead," he said without emotion. "Brute not lie."

Dismayed fury erupted through Goat's veins and a red haze swept over his eyes.

"You idiot!" he squawked. "So that won't kill you?"

Goaded beyond endurance, Goat seized the knife and swung it as hard as he could against Brute's neck. It thunked like an ax biting into a tree trunk, biting halfway through the flesh. Brute recoiled at the impact, tearing the handle from Goat's feeble hands and leaving the knife blade stuck in his throat.

Brute staggered momentarily. Then he reached up and jerked the knife away. Blood spurted through his severed throat. Brute clapped a hand to the wound, tightly.

For a moment, blood oozed through his fingers. Then, pale but steady, Brute dropped his hand.

The wound had closed! Its edges already were sealed, leaving a raw, red scar that no longer bled.

"Brute not lie," said Brute, the words forced out with some difficulty. "It not kill Brute."

Stunned by astonishment and disbelief, Goat stared at him, his mouth moving soundlessly.

"Go away," he whispered hoarsely at last. "Go out of here, monster!"

Obediently, Brute shambled out of the study. As he passed through the door, Goat regained his voice and called after him:

"Tell the children to come and take away Adam's body."

---

Kilometers away, Maya Cara Nome and S. Nuwell Eli rode a groundcar that moved swiftly across the interminable waves of the red sand. It swayed through hollows and jounced over multiple ridges, Nuwell steering it with some difficulty. In the steely sky, the small sun moved downward, its brightness unimpaired by the occasional thin clouds which moved before it.

The sun touched the western horizon, seemed to hesitate, dropped with breathtaking suddenness, and the stars immediately began to appear in the deepening twilight sky.

They stopped and had a compact meal, heated in the groundcar's short-wave cooker. Then Nuwell switched on the headlights and they went on again.

Soon afterward, a faint spot of light appeared in the desert far ahead of them. As they approached it, it became a yellow-lighted window in a huge black mass rearing up against the night sky. They had reached Ultra Vires.

Nuwell announced their arrival over the groundcar radio and swung the groundcar up beside the building's main entrance. He sealed the groundcar's door to the building air-lock so they would not have to don marsuits.

After a few moments, the airlock opened. They passed through it and were greeted by a skinny, shriveled little man with watery blue eyes and a goatee.

"I was expecting you, but not tonight," said this person, rather sourly. "Well, come on in and I'll have the children fix you something to eat if you haven't eaten."

"I'm S. Nuwell Eli," said Nuwell, holding out a hand which the other ignored. "This is the terrestrial agent, Miss Maya Cara Nome. You are Dr. Hennessey, I assume."

"That's right," said Goat. "Do you want supper?"

"No, thank you, we ate on the way," said Nuwell. "I'd like to get started with the inspection as soon as possible."

"Inspection or investigation?" suggested Goat, sniffling. "Well, no matter. I have nothing to hide."

He led them down a dim, dusty corridor, stretching deep into the dark bowels of the building, and turned aside into a paper-stacked room which evidently was his study. He went straight to a big desk, sat down, swivelled his chair around and waved them to seats. Nuwell shuffled a little uncomfortably, then sank into a chair, but Maya remained standing by the door, her small traveling bag in her hand, indignation rising in her.

"Before you settle down to charts and questions, Dr. Hennessey, do you mind showing us to our rooms so we may wash away some of the travel dust?" she asked icily, black eyes snapping.

At this, Goat jumped to his feet, sincere contrition in his face wiping out all traces of his irritated gruffness.

"I'm very sorry!" he exclaimed. "I hope you will forgive my manners, but I've lived and worked here alone in the desert so long that I had forgotten the niceties of civilization."

This apology cleared the air. Goat showed them their overnight quarters, adjoining rooms which were not luxurious but were reasonably comfortable, and after a time the three of them congregated once more in Goat's study, all of them in better humor.

"Let us have some wine first," suggested Goat. "This is very good red wine, imported from Earth."

He went to the door and shouted into the corridor.

"Petway!"

Goat returned to his chair. A few moments later, a twittering noise sounded in the corridor, then a horrible little apparition appeared in the door. It was a child-sized creature, naked, grotesquely barrel-chested and teetering on thin, twisted legs. Its hairless head was skull-like, with gaping mouth and huge, round eyes.

Maya gasped, profoundly shocked. The little creature looked more like a miniature Martian native than a human, but the Martians themselves were not so distorted. She saw her own shock reflected in Nuwell's face.

"Petway, get us three glasses of wine," commanded Goat calmly.

Petway vanished and Goat turned briskly back to his guests.

"Now," he said, "I shall outline the progress of my experiments to you and answer any questions you may have."

---