the ship, our chances are rather
slim. We'll just have to wait until we get a break."

* * * * *

As the day wore on there was a note of menace in the silence that hung
over the Trap-Door City. It was nothing tangible, unless it was the
appearance of two long silvery rods mounted on the top of the huge
cocoon-palace of the Queen aiming down at Helgers' ship. Penrun could
have sworn they were not there yesterday. The sight of them made him
uneasy.

Helgers must have interpreted the silence differently, for presently a
man emerged from the ship, protected against the heat by a clumsy
space-suit. He hesitated, then walked slowly away from the ship, and
paused again, waiting for the spiders to attack. Not a movement was
made in the city. Presently he moved on again toward the cataract
which had dwindled in the heat of the day to a mere trickle of hot
water down to the pool in the gorge more than half a mile below.

After a time the man reached the cataract. He descended the short path
that led down under the lip of rock to another ledge a few feet below
it. The entrance to the Caves opened out onto this lower ledge. Little
wonder, thought Penrun, that no one knew where the Caves were.

Some time later two other men from the ship followed him.

"Fools!" muttered Penrun, following them through his glasses. "They
think the spiders are afraid of their ray artillery. I'll bet the
monsters are either waiting until all the men wander out of the ship,
or else they're getting ready to spring some hellish surprise."

Other men came out of the ship, carrying rock drills, a roll of cable
and a powerful little windlass. Instead of going to the Caves, they
went round the ship to the other side under the doubtful protection of
the ray-guns, and sank two shafts into the granite. Into these they
drove steel posts and anchored the windlass. One end of the cable was
attached to the windlass and the other to the nose of the ship. Then
they slowly dragged the big craft across the plateau on rollers from
the ship's store room.

* * * * *

"That's strange!" exclaimed Penrun. "The ship can't rise! I wonder
what's wrong, and why they are pulling it away from instead of toward
the Caves."

"I don't know what's the matter with the ship, but I believe I know
why they are moving it," volunteered Irma. "They're taking it to that
hiding-place I told you Helgers picked out--there be