nd, Chief. See where I am?"]

_If the ocean water were gone! Can you picture it? A new world, greater
in area than all the land we now have. They would call the former
sea-level the zero-height, perhaps. The depths would go down as far
beneath it as Mount Everest towers above it. Aeroplanes would fly down
into them._

_And I can imagine the settlement of these vast new realms: New little
nations being created, born of man's indomitable will to conquer every
adverse condition of inhospitable nature._

_A novel setting for a story of adventure. It seems so to me. Can you
say that the oceans will never drain of their water? That an earthquake
will not open a rift--some day in the future--and lower the water into
subterranean caverns? The volume of water of all the oceans is no more
to the volume of the earth than a tissue paper wrapping on an orange._

_Is it too great a fantasy? Why, reading the facts of what happened in
1929, it is already prognosticated. The fishing banks off the Coast of
Newfoundland have suddenly sunk. Cable ships repairing a broken cable,
snapped by the earthquake of November 18th, 1929, report that for
distances of a hundred miles on the Grand Banks the cables have
disappeared into unfathomable depths. And before the subterranean
cataclysm, they were within six hundred feet of the surface. And all the
bottom of that section of the North Atlantic seems to have caved in. Ten
thousand square miles dropped out of the bottom of the ocean! Fact, not
fancy._

_And so let us enlarge the picture. Let us create the Lowlands--twenty
thousand feet below the zero-height--the setting for a tale of
adventure. The romance of the mist-shrouded deeps. And the romance of
little Jetta._

CHAPTER I

_The Secret Mission_

I was twenty-five years of age that May evening of 2020 when they sent
me south into the Lowlands. I had been in the National Detective Service
Bureau, and then was transferred to the Customs Department, Atlantic
Lowlands Branch. I went alone; it was best, my commander thought. An
assignment needing diplomacy rather than a show of force.

It was 9 P. M. when I catapulted from the little stage of Long Island
airport. A fair, moonlit evening--a moon just beyond the full, rising to
pale the eastern stars. I climbed about a thousand feet, swung over the
headlands of the Hook, and, keeping in the thousand-foot local lane,
took my course.

My destination lay some thirteen hundred miles so