accompanied by
two of the men--the third was working on the surface--and there unload
them. Day after day this continued.

Hope of escaping was almost dead in Parkinson's breast, because he
was constantly under the surveillance of those hard, blue eyes. Only
one thing kept hope alive: by watching the Venerians operate the car,
he was slowly gaining a knowledge of the meaning of the many buttons
in the wall. Some day, if an opportunity came, he meant to be ready to
take advantage of it.

Once, shortly after his monotonous toil began, Parkinson experienced a
great flare of hope for deliverance. They had just brought another
slab to the surface, when a steamer appeared above the horizon. It was
far away, but its crew must surely have seen the island.

But his expectations were short-lived. One of the three drew from
beneath his tight-fitting, white garments a little, metal object, a
long tube, with a handle at one end, and pointed it at the vessel. For
a moment he held it thus, moving it slowly backward and forward: then
he returned it to its place of concealment, and turned away with an
air of indifference. And Parkinson saw the ship burst suddenly into
flame, a few minutes later to sink beneath the waves.

* * * * *

Shaken to the depths of his being, Parkinson resumed his work. The
inhumanity of these saturnine Venerians filled him with a dread so
great that he refused to admit it to himself. That that had not been
the first time that they had destroyed a ship, he felt sure; his heart
sank, and grew more hopeless.

At last his task of carrying slabs was finished. The room was empty,
and the work completed. A great tower, entirely covering the island,
reared its head into the sky. In appearance, it resembled a very tall
lighthouse. This resemblance held true only until its top was reached;
there it ended. From the tower's top extended four long, hollow arms,
so constructed that they whirled about the tower at a mad pace when
the machinery with which they were connected was started. In addition,
arrangement was made for a powerful blast of air to be sent through
the tubes when the Venerians so desired.

What the purpose of this great edifice was, Parkinson could not guess:
later, he learned the horrible significance of it all.

After the tower was finished, the bacteriologist was left to his own
devices to a great extent, though always closely watched by one of his
captors. They l