The destination was a lone, sprawling building in the desert. It could
have been a huge warehouse, or a fortress, of black, almost windowless
Martian stone. The only outstanding feature of its virtually featureless
hulk was a tower which struck upward from its northern side.

As the summer afternoon progressed, Dr. G. O. T. Hennessey paced the
windy summit of the tower, peered frequently into the desert north
beneath a sunshading hand, and waggled his goat beard in annoyance under
his transparent marshelmet.

Had the helmet speaker been on or the air less thin, one might have
determined that Goat Hennessey was utilizing some choice profanity,
directed at those two absent personages whose names were, respectively,
Adam and Brute.

The airlock to the tower elevator opened and a small creature--a
child?--emerged onto the roof. Distorted, humpbacked and
barrel-chested, it scuttled on reed-thin legs to Goat's side. It wore no
marsuit.

"Father!" screeched this apparition, its thin voice curiously muffled by
the tenuous air. "Petway fell in the laundry vat!"

"For the love of space!" muttered Goat in exasperation. "Is there water
in it?"

When the newcomer gave no sign of hearing, Goat realized his helmet
speaker was off. He switched it on.

"Is there water in the vat?" he repeated.

"Yes, sir. It's full of suds and clothes."

"Well, go fish him out before he soaks up all the water. The soap will
make him sick."

The messenger turned, almost tripping over its own broad feet, and went
back through the airlock. Goat returned to his northward vigil.

Miles away, Nuwell slowed the groundcar as it approached the lip of that
precipitous slope bordering the short canal which connects Juventae Fons
with the Arorae Sinus Lowland. He consulted a rough chart, and turned
the groundcar southward. A drive of about a kilometer brought them to a
wide descending ledge down which they were able to drive into the canal.

Here, on the flat lowland surface, the canal sage grew thick, a
gray-green expanse stretching unbroken to the distant cliff that was the
other side of the canal. Occasionally above its smoothness thrust the
giant barrel of a canal cactus.

Nuwell headed the groundcar straight across the canal, for the chart
showed that the nearest upward ledge on the other side was conveniently
almost opposite. The big wheels bent and crushed the canal sage, leaving
a double trail.

The canal sage brought with it the comfort