arded. But all the flying things he saw were two moth birds of
delicate hues engaging far over the sun-baked rock in one of their
graceful winged dances.

They crossed the heights and came to the inland slope, a drop toward
the central interior plains of the continent. As they plowed through
the high grasses Dalgard knew they were under observation. Hoppers
watched them. And once through a break in a line of trees he saw a
small herd of duocorns race into the shelter of a wood. The presence
of those two-horned creatures, so like the pictures he had seen of
Terran horses, was insurance that the snake-devils did not hunt in
this district, for the swift-footed duocorns were never found within a
day's journey of their archenemies.

Late afternoon faded into the long summer twilight and still Sssuri
kept on. As yet they had come across no traces of Those Others. Here
were none of the domed farm buildings, the monorail tracks, the other
relics one could find about Homeport. This wide-open land could have
been always a wilderness, left to the animals of Astra for their own.
Dalgard speculated upon that, his busy imagination supplying various
reasons for such tract. Then the voiceless communication of his
companion provided an explanation.

"This was barrier land."

"What?"

Sssuri turned his head. His round eyes which blinked so seldom stared
into Dalgard's as if by the intensity of that gaze he could drive home
deeper his point.

"What lies to the north was protected in the days before the falling
fire. Even _Those_"--the distorted mermen symbol for Those Others was
sharpened by the very hatred of all Sssuri's kind, which had not paled
during the generations since their escape from slavery to Astra's
one-time masters--"could not venture into some of their own private
places without special leave. It is perhaps true that the city we are
seeking is one of those restricted ones and that this wilderness is a
boundary for it."

Dalgard's pace slowed. To venture into a section of land which had
been used as a barrier to protect some secret of Those Others was a
highly risky affair. The first expedition sent out from Homeport after
the landing of the Terran refugee ship had been shot down by
robot-controlled guns still set against some long-dead invader. Would
this territory be so guarded? If so they had better go carefully now--

Sssuri suddenly struck off at an angle, heading not northeast now, but
directly north. The b