CHAPTER I

  _The Secret Mission_

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

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

  My destination lay some thirteen hundred miles southeast of Great NewYork. I could do a good normal three-ninety in this fleet little Wasp,especially if I kept in the rarer air-pressures over the zero-height.The thousand-foot lane had a southward drift, this night. I was makingnow well over four hundred; I would reach Nareda soon after midnight.

  The Continental Shelf slid beneath me, dropping away as my course tookme further from the Highland borders. The Lowlands lay patched with inkyshadows and splashes of moonlight. Domes with upstanding, rounded heads;plateaus of naked black rock, ten thousand feet below the zero-height;trenches, like valleys, ridged and pitted, naked in places like apockmarked lunar landscape. Or again, a pall of black mist wouldshroud it all, dark curtain of sluggish cloud with moonlight tinging itsedges pallid green.

  To my left, eastward toward the great basin of the mid-AtlanticLowlands, there was always a steady downward slope. To the right, itcame up over the continental shelf to the Highlands of the UnitedStates.

  There was often water to be seen in these Lowlands. A spring-fed lakefar down in a caldron pit, spilling into a trench; low-lying,land-locked little seas; canyons, some of them dry, others filled withtumultuous flowing water. Or great gashes with water sluggishly flowing,or standing with a heavy slime, and a pall of uprising vapor in the heatof the night.

  At 37 deg.N. and 70 deg.W., I passed over the newly named Atlas Sea. Alake of water here, more than a hundred miles in extent. Its surfacelay fifteen thousand feet below the zero-height; its depth in places wasa full three thousand. It was clear of mist to-night. The moonlightshimmered on its rippled surface, like pictures my father had oftenshown me of the former oceans.

  I passed, a little later, well to the westward of the verdured mountaintop of the Bermudas.

  There was nothing of this flight novel to me. I had frequently flownover the Lowlands; I had descended into them many times. But never uponsuch a mission as was taking me there now.

  I was headed for Nareda, capital village of the tiny Lowland Republic ofNareda, which only five years ago came into national being as aprotectorate of the United States. Its territory lies just north of themountain Highlands of Haiti, Santo Domingo and Porto Rico. A few hundredmiles of tumbled Lowlands, embracing the turgid Nares Sea, whose bottomis the lowest point of all the Western Hemisphere--some thirty thousandfeet below the zero-height.

  The village of Nareda is far down indeed. I had never been there. Mycharts showed it on the southern border of the Nares Sea, at minustwenty thousand feet, with the Mona Valley behind it like a gash in thesteep upward slopes to the Highlands of Porto Rico and Haiti.

  Nareda has a mixed population of typical Lowland adventures, among whichthe hardy Dutch predominate; and Holland and the United States havecombined their influence in the World Court to give it nationalidentity.

  * * * * *

  And out of this had arisen my mission now. Mercury--the quicksilver ofcommerce--so recently come to tremendous value through its universal usein the new antiseptics which bid fair to check all human disease--wasbeing produced in Nareda. The import duty into the United States wasbeing paid openly enough. But nevertheless Hanley's agents believed thatsmuggling was taking place.

  It was to investigate this condition that Hanley was sending me. I hadintroduction to the Nareda government officials. I was to consult withHanley by ether-phone in seeking the hidden source of the contrabandquicksilver, but, in the main, to use my own judgment.

  A mission of diplomacy. I had no mind to pry openly among the people ofthese Lowland depths, looking for smugglers. I might, indeed, find themtoo unexpectedly! Over-curious strangers are not welcomed by theLowlanders. Many have gone into the depths and have never returned....

  I was above the Nares Sea, by midnight. I was still flying a thousandfeet over the zero-height. Twenty-one thousand feet below me lay theblack expanse of water. The moon had climbed well toward the zenith,now. Its silver shafts penetrated the hanging mist-stratas. The surfaceof the Nares Sea was visible--dark and sullen looking.

  I shifted the angles of incidence of the wings, re-set my propellerangles and made the necessary carburetor adjustments, switching on thesupercharger which would supply air at normal zero-height pressure tothe carburetors throughout my descent.

  I swung over Nareda. The lights of the little village, far down, dwarfedby distance, showed like bleary, winking eyes through the mists. Thejagged recesses of the Mona valley were dark with shadow. The Nares Sealay like some black monster asleep, and slowly, heavily panting.Moonlight was over me, with stars and fleecy white clouds. Calm, placid,atmospheric night was up here. But beneath, it all seemed so mysterious,fantastic, sinister.

  My heart was pounding as I put the Wasp into a spiral and forced my waydown.