"
muttered Astro grimly.

For eight days they had been struggling across the blistering shifting
sands, walking by night, sweltering under the thin space cloth during
the day. Their tongues were swollen. Scraggly beards covered their chins
and jaws. Roger's lips were cracked. The back of Tom's neck had suffered
ten minutes of direct sun and turned into a large swollen blister. Only
Astro appeared to be bearing up under the ordeal. There was no sign of
their being close to the canal.

"Wanta try marching during the day?" asked Astro. They had broken camp
on the evening of the eighth day and were preparing to move on into the
never-changing desert.

"If we don't hit the canal sometime during the night, there might be a
chance it's close enough to reach in a couple of hours," replied Tom.
"Either that, or we've miscalculated altogether."

"How about you, Roger?" asked Astro.

"Whatever you guys decide, I'll be right in back of you." Roger had
grown steadily weaker during the last three days and found it difficult
to sleep during the hours of rest.

"Then we'll keep marching tomorrow," said Astro.

"Let's move out," said Tom. Roger and Astro shouldered the remaining
slender food packs, with Tom carrying the water and space cloth, and
they started out into the rapidly darkening desert.

Once again, as on the previous eight nights, the little moon, Deimos,
swung across the sky, casting dim shadows ahead of the three marching
boys. Tom found it necessary to look at the compass more often. He
couldn't trust his sense of direction as much as he had earlier. Once,
he had gone for two hours in a direction that was fifty degrees off
course. The rest stops also were more frequent now, with each boy
throwing his pack to the ground and lying flat on his back, to enjoy the
cool breeze that never failed to soothe their scorched faces.

When the sun rose out of the desert on the morning of the ninth day,
they stopped, ate a light breakfast of preserved figs, divided the juice
evenly among them, and, ripping the space cloth into three sections,
wrapped it around themselves like Arabs and continued to walk.

By noon, with the sun directly overhead, they were staggering. At
two-thirty the sun and the heat were so overpowering that they stopped
involuntarily and tried to sit on the hot sand only to find that they
couldn't and so they stumbled on.

Neither Roger nor Astro asked for water. Finally Tom stopped and faced
his two un