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 f