You will understand what I mean when you consider that the sun of our solar system is too greatly distant from Callisto to be particularly visible, save as one of the more brilliant stars. On Earth, navigation by means of solar observations is the simplest of feats; the sun rises in the east, traverses the dome of the sky, and sets in the west; hence, at any given hour of the day one can at least ascertain the cardinal directions in general at a glance.
Not so on Thanator, As well, the heavens of the jungle Moon are thickly obscured by crawling golden vapors, as I have remarked earlier; hence, navigation by study of the fixed stars or constellations is also virtually impossible.
True, the larger of Callisto’s sister moons of Jupiter are visible orbs of colored light during the hours of darkness, but even here a problem imposes itself. For the Jovian moons, at least the larger ones, circumnavigate their primary in a system or orbits of bewildering complexity. It is a mathematical problem of truly staggering difficulties, attempting to navigate the skies of Thanator at night, guided only by the positions of the moons of Jupiter.
“I see what you mean, Haakon,” I said ruefully. “But let us not worry about problems that may soon correct themselves unaided. The cloud zone may soon break up, and the clouds disperse, permitting us to obtain clear visibility of the land below.”
“Perhaps, sir, but perhaps not,” Haakon gravely remarked. “But if so, it must occur very soon, or it will do us no good at all. For night is almost upon us.”
I should perhaps explain here that the peculiar and inexplicable illumination of the golden vapor that fills the skies of Callisto ceases with startling unanimity at nightfall. On Earth the solar orb declines gradually into sunset, twilight and afterglow, but on Callisto, when day ends, the transition is one of surprising suddenness. One moment the Jungle Moon is bathed in ubiquitous golden radiance―the next, it is plunged into total darkness. Hence, unless the clouds broke very soon, so that we could obtain clear sightings of major landmarks by which to correct our course and orient our flight, the eventual dispersal of the vapors would do no good at all.
“Well,” I said, “let us hope our course is undeviating.” The grizzled senior officer shook his head reluctantly.
“We have been meeting a slight but definite headwind for the past hour or two,” he confessed. “I have been compensating for it more or less by pure guesswork, but if we must fly blind during the entire night, compensating against this headwind, our course by morning may have been deflected off true northwest by a wide margin. If only, sir, we had the assistance of an experienced pilot. But I assume our prisoner remains obdurately uncooperative?”
I nodded. Captain Ulthar had steadfastly refused to lend us any assistance whatsoever. Bidding Haakon to continue compensating for the headwind and to summon me to the cupola should there be any change at all in the weather conditions, I descended by the circular stair into the captain’s cabin to consult the Zanadarian navigational guides. I did not expect these to be of any real help, nor were they.
Lacking sun or moon or stars, navigation through the skies of Thanator is a highly complex art. The Sky Pirates who command the aerial vessels are seasoned and experienced veterans and doubtless know the winds and ways of the Thanatorian heavens from past familiarity. However, the galleon’s cabin was supplied with certain standard guides, among which was a sort of sky atlas which charted the major prevailing winds which were bewilderingly complicated beyond the abilities of a mere novice to quickly master. I puzzled over the atlas but could make nothing of its cryptic notations. The guidebooks also included an ephemeris of the orbits of the visible moons of Jupiter, but these also were exceedingly complex. True, they charted the variations in the lunar positions and related these to the cardinal directions, but the variations were minute and intertwined, and, lacking a compass―an invention for which the Thanatorians seem to lack reason to develop―we would, it seemed, be flying blind during the hours of darkness.
There was really nothing we could do about this. Difficulties in navigation were among the several unknown factors we had risked in attempting this voyage into the unknown. Ostensibly, it had seemed remarkably simple to traverse the land surface of Callisto between Shondakor and Zanadar. The City in the Clouds lies north by northwest of the realm of the Ku Thad, and it would seem an easy task to fly thither. You pass the plains, traverse the Grand Kumala, enter the northerly mountain country, and simply look about for the mountaintop city of the Sky Pirates. Nothing could have been simpler, or so it seemed at the beginning.
Night fell without a break in the cloud blanket. We flew on into darkness, still battling against an unsteady headwind that pushed against our prow and strove in uneven gusts to drive us east.
At the captain’s table, over dinner that evening, our navigational difficulties were the central topic of discussion. Our captive, Ulthar, who ate with us, being an officer of noble birth, smiled gently when peppery old Lukor loudly and pointedly suggested he might place his knowledge and experience at our service.
“I am certain the gentleman of Ganatol would not seriously suggest violating the terms under which I have given Captain Jandar my parole,” he said mockingly. “The nobly born gentleman will recall that our agreement does not include my revealing the secrets of my people, among which the art of aerial navigation must surely be numbered.”
Lukor screwed up his face in an expression of disgust.
“I had assumed the nobly born gentleman of Zanadar would have yielded to reason,” he said acerbically, “if only since to keep silence in this danger imperils his life as well as ours!”
Ulthar laughed quietly, and turned hooded, mocking eyes upon me. “It would seem, Captain Jandar, that my faith in your exceptional abilities is greater than that of those you are pleased to call your friends. For, unlike them, I have no fears that you will prove unable to meet this present minor emergency.”
Lukor growled a colorful oath and addressed himself to his plate. Ulthar remained quiet but observant throughout the remainder of the meal.
The cabin lamp swayed on its creaking chain as the great galleon of the skies trembled to the buffets of the tailwind. Wine sloshed in our goblets; plates slid to and fro on the table.
We ate in silence, each busied with his own thoughts. My own were far off in the mountaintop citadel of our foes, the remorseless and rapacious Sky Pirates of Zanadar. I wondered how my beloved Darloona fared at this hour. Had she given over all hope of rescue by now?
The meal finished, we each sought our bunks and uneasy and troubled slumbers. All that night we flew on into mystery, wondering where dawn would find us.
We awoke in an unknown world.
Book II
OFF THE MAP
Chapter 4
THE UNKNOWN SEA
Before dawn I arose from a night of broken and uneasy slumbers, through which I had tossed and turned continuously, my rest disturbed and troubled by ominous dreams.
Rising from my bunk, I hastily threw on my wide-sleeved white blouse, thigh-length leather tunic, calf-high boots and cloak, girdle, and sword-belt, and went up on deck to observe the sudden miracle of daybreak on Thanator.
The reader can, I am sure, envision the extent of my distress as I looked over the side upon an unknown portion of the surface of Thanator.
The swift, brilliant dawn had illuminated the world from horizon to horizon, banishing the darkness that had long enshrouded the surface of the jungle Moon.