rbo to remain close to Carruthers at
all times. So the young scientist left the cavern and ascended the
path leading to the top of the plateau. He looked at his watch and
compared the second hand with the nucleus atom sailing across the
heavens to estimate its speed.

* * * * *

Days passed as he made his observations. Meanwhile he had searched and
found the exact spot wherein he and Nanette had first stepped foot
onto the electron. This spot he carefully marked off with a ring of
huge boulders carried up by the followers of Marbo. Then he began to
calculate upon his pad. There must be no mistakes. He and Nanette must
be within the magic circle at the estimated time.

Between times he helped Nanette construct their living quarters in the
cavern. Zark had furnished them with skins and furs with which to
cover the walls. Carruthers made a fireplace of stones and restored
the lost art of fire to Zark, Marbo and their followers.

Days slipped by like minutes. Short days filled with excursions into
the jungles. Carruthers' face soon bristled with a stubble of beard.
This lengthened with time. Sharp thorns tore their clothes to ribbons.
Nanette, womanlike, cried many times during the nights because of the
lack of a mirror and a comb for her untidy hair.

But other and more important events soon claimed the attention of the
earth people. Day by day the herds of dinosaurs and other monsters of
like breed edged closer and closer to the tiny civilization around the
plateau. It worried Carruthers so much that he sought out Zark and had
him bring the other six members of his tribe together for a council of
war.

"A complete defensive system, Zark," he told them. "We must make a
fortress of the plateau and fill the caverns with food."

* * * * *

Zark shook his head. "No. It is quite useless. Followers of Marbo have
recently returned from over the beyond and report strange things. I
have hesitated to speak of them for fear of alarming you. Our planet
is breaking up. Violent eruptions have caused fires of stone and mud.
The rumblings you have heard were not made entirely by our enemies.
They came from the ground.

"An earthquake," murmured Carruthers, momentarily stunned by the news.
"But they are always of short duration, Zark. We have them on our own
planet."

"Ah, but these are different. They cover the whole of our globe. The
great Dahlgren noted them whil