y would overflow
the sides of the pool and submerge the floor of the chamber.

For a moment I did not fully grasp the terrible import of the slowly
rising water. It was Carthoris who realized the full meaning of the
thing--its cause and the reason for it.

"Haste!" he cried. "If we delay, we all are lost. The pumps of Omean
have been stopped. They would drown us like rats in a trap. We must
reach the upper levels of the pits in advance of the flood or we shall
never reach them. Come."

"Lead the way, Carthoris," I cried. "We will follow."

At my command, the youth leaped into one of the corridors, and in
column of twos the soldiers followed him in good order, each company
entering the corridor only at the command of its dwar, or captain.

Before the last company filed from the chamber the water was ankle
deep, and that the men were nervous was quite evident. Entirely
unaccustomed to water except in quantities sufficient for drinking and
bathing purposes the red Martians instinctively shrank from it in such
formidable depths and menacing activity. That they were undaunted
while it swirled and eddied about their ankles, spoke well for their
bravery and their discipline.

I was the last to leave the chamber of the submarine, and as I followed
the rear of the column toward the corridor, I moved through water to my
knees. The corridor, too, was flooded to the same depth, for its floor
was on a level with the floor of the chamber from which it led, nor was
there any perceptible rise for many yards.

The march of the troops through the corridor was as rapid as was
consistent with the number of men that moved through so narrow a
passage, but it was not ample to permit us to gain appreciably on the
pursuing tide. As the level of the passage rose, so, too, did the
waters rise until it soon became apparent to me, who brought up the
rear, that they were gaining rapidly upon us. I could understand the
reason for this, as with the narrowing expanse of Omean as the waters
rose toward the apex of its dome, the rapidity of its rise would
increase in inverse ratio to the ever-lessening space to be filled.

Long ere the last of the column could hope to reach the upper pits
which lay above the danger point I was convinced that the waters would
surge after us in overwhelming volume, and that fully half the
expedition would be snuffed out.

As I cast about for some means of saving as many as possible of the
doomed men,