CHAPTER XI

  THE MYSTERY AIRSHIP

  "I say, Jack!" Perk called, making use of the friendly ear-phones.

  "What's eating you, buddy?" demanded the other, who must have known fromhis comrade's shifting about so much there was something amiss.

  "Did yeou hear it?" asked Perk, anxiously.

  "You mean that sound in the fog pack, don't you?" Jack countered.

  "Yeah, yeou said it, partner--I kinder guess naow it was a ship up herein this same sea we're buzzin' through, don't yeou?"

  "Couldn't be anything else, because we're thousands of feet away fromground," Jack admitted; and somehow it gave his chum a feeling of reliefto notice how his voice showed no signs of sudden alarm.

  "As haow would yeou make it eout to be--some bewildered air-mail pilotloose in his bearin's, and shootin' ahead, thinkin' he could getsomewhere right speedy, so's to find his course agin?"

  "Not any, Perk; and you'll realize that much if you figure things out ina matter-of-fact way. They don't have greenhorns in the air-mailservice, or carrying passengers on the big lines--every applicant for ajob has got to have a thousand hours at least in the air, and even atthat he isn't reckoned to have won his spurs. If such an experiencedflier got balled up in this fog blanket he'd do just what we're carryingout--depend utterly on his instruments. His compass would tell him hecould never regain his course by flying _due east_!"

  "That's what he's adoin' then, yeou figger, eh, Jack?"

  "Sure thing, boy--he's directly behind us, and getting closer rightalong, for the sounds keep growing louder."

  "Guess that's so, partner--I kinder had an idee he was on aour tail.What's the answer, Jack?"

  "Another dive, maybe two in fact, so as to leave him this ceiling tohimself. We can climb again, buddy, after he's passed us, and pushesfurther on his way. That's the only sensible thing to do."

  Perk had been allowing his mind to picture a battle royal up there incloudland, amidst the fog mists, where machine-guns might rattle just asyears ago they always did when bitter foes over on the French bordercame in contact, while bent on forays that took them on long airvoyages, to bomb forbidding ammunition dumps, and thickly mannedtrenches back of No Man's Land.

  In imagination he had already heard the terrible long roll being soundedby the chattering quick-firing guns; with a hail of missiles sweepingall around them, like a swarm of enraged hornets as experienced in hisown boyhood days.

  But Jack, who kept his imagination under better control, did not look atthings in the same way--his idea was not to accept the gage of battlewhen diplomacy and clever tactics could shift it on to some future date,when the chances might be more in their favor.

  What a partner to have at your side when things looked more or lessdubious--Perk drew a long breath as of relief, and inwardly blessed theday he paired up with Jack Ralston.

  There, once more they were shooting almost straight down into thatbewildering sea of fog. It could not but give even seasoned Perk thethrill of his life, as he contemplated what would happen should theydash against some isolated mountain crag or peak, while rushing along atthis tremendous speed.

  He held his breath during the score of seconds they occupied in thusseeking another ceiling. Then the quivering ship, under Jack's skillfulguidance, glided into a level course, and Perk breathed naturally oncemore.

  While the swift descent continued he had listened intently, and wasoverjoyed to note how the distinct clamor of the other plane's motorgradually grew fainter, thus proving that they must be increasing thedistance separating the two hidden airships.

  Jack, one eye on his altitude instrument, even brought about anotherdip, during which Perk failed to catch even the faintest mutter of aworking motor; which fact seemed to prove beyond dispute their objecthad been achieved--the unseen flying craft had been given all rights tothat upper ceiling, and all danger of a chance collision in the skylanes was avoided, at least for the time being.

  They were still heading into the east, with a shade running towardnortheast, as though Jack continued to hold fast to his belief they werefollowing the proper course. It required the most wonderful grasp uponthe situation, as Perk well knew, to keep going so confidently throughsuch an ocean of dense fog, utterly unable to see any obstaclethreatening them ahead.

  Perk, absolutely content to leave all matters of this sort in the handsof the partner who had never as yet failed him in a pinch, found himselfwondering what that decision, given so assuredly by his companion, mightsignify--if not a lost air-mail pilot, then who could the unknownvoyager, shooting so recklessly through the pea-soup sea, be?

  They were again ascending, proving that Jack understood what additionalchances for a mishap they were tempting at the lower level, and wishedto play safe as soon as he could do so with the unknown ship havingpassed on into the unseen vacuum ahead.

  Again did the temperature approach close to the freezing point, and nowonder, with their ship soaring at such a height; but in that part ofthe mountainous country they must expect to find lofty uplifts mountingto the clouds, many thousands of feet above all comfortable atmosphere.

  Perk busied himself in moving around, following such duties as devolvedon his shoulders while his partner handled the stick. His chief concernlay in the direction of finding out just when the dense vapor began toform a thin coating of ice on the wings.

  With the coming of such an insidious enemy their danger increasedten-fold, since by degrees it would add enough weight to the alreadyheavily laden ship as to force it down all too speedily, with whathidden perils lying in wait below as only a lively imagination couldvision.

  Still that question remained unanswered--try as he might Perk seemedunable to successfully grapple with so puzzling and knotty a problem--ifnot a mail pilot off his course, nor yet some enemy trying to overtake,and run them down in midair, then who could it be?

  With Perk bewildered the matter must inevitably settle down to one wellpracticed means for finding the answer to the enigma--"ask Jack--heknows"--a formula as simple as anything could be, also shifting allresponsibility to other shoulders.

  Perk went at it again, and asked for light.

  "Mebbe naow, partner," he called out, "it might be yeou guessed thiscrazy flier up yonder was some madcap pilot atryin' to beat the recordgoin' east from coast to coast; or else a locoed lad carryin' apassenger who'd lose his hull fortune if so be he didn't land in WallStreet inside so many hours."

  Jack laughed, as though amused at these vague stabs--he knew what theother had in his mind by going on in this fashion.

  "Just fishing again, eh, Perk--want to know what I think covering thegame, isn't that so? Well, listen, and I'll put a flea in your ear."

  "Go to it, partner--I'm agreeable, an' wantin' to be informed," Perkhastened to say.

  "Among those documents I examined there was one fact I laid some stresson, which consisted of a statement that the Secret Service man who senthis report in, and then seemed to disappear utterly from the knowledgeof all men, declared it to be his opinion these hideout big guns in thecriminal world, working under our old friend Slippery Slim Garrabrant,had some sort of an _airship_, with which they were doing a rattlinggood business--perhaps you slipped up on that particular fact; but Ifigured we might run across that plane, sooner or later, and haveconsiderable bother with the same."

  "Hot-diggetty-dig! then Jack, you mean it could a been that crate weheard abeatin' time on aour tail; an' mebbe chasin' us like hotbeans--tell me, is that what hits you so hard, matey?"

  "I have a pretty strong idea it was their ship, covering a well-knowncourse from the coast to this valley in the rocky unknown territory toorough even to have been explored, as it was believed to be worthless foreven mining purposes. As to whether those aboard were trying to strikeus in the fog, that's still a mystery, and must remain such for thepresent."

  "Then do yeou guess they knowed we was ahead on the same track, eh,Jack, ole hoss?"


  "Remember Perk, that as far as we know they didn't change their ceilingat any time--just kept booming away at the same level. That being thecase they couldn't have heard the sound of our own motor working, astheir exhaust would deafen them completely; for we only caught theracket behind us when we were shooting the shoot, with our engineshut-off."

  "Good enough for us, buddy--then we got a clear field ahead, an' c'nfoller aour own plans right along."

  "For the time being; but don't forget we've got rough sledding ahead. Itall depends on how long we'll be held fast in the grip of this accursedfog pack. Running blind isn't a very satisfactory way of getting along,especially when you only know the country through rude charts that maybe all right, and then again sprinkled with errors that are bound to befull of danger to us."

  "Hit an' miss, Jack, we're used to takin' the chances--it's all a parto' the followin' we're rappin' in. We jest got to do aour best, an'leave the rest--aint I been adoin' that same mighty near all my wholelife? an' seems like little ole Perk he's still on deck, able to eat histhree good meals a day--whenever he c'n git the same."

  "It's after midnight, Perk."

  "So it be, partner; an' we muster gone a good many hundred miles sincejumpin' off--strikes me we orter be clost to the goal we had in aourminds; if so be we been keepin' on a di-reck course, with no wabblin' tocheck us aout."

  "I figure that way myself," replied Jack; "but nothing can be done tomake certain until conditions change for the better."

  "Which would mean we got some hours to kill, 'fore mornin' comes alongto give us a show fur aour money, eh, Jack, ole boy?"

  "There's only one way to do that," snapped the other; "which is bycircling around, keeping our altitude, and within a range of say fiftymiles; and that's what I'm aiming to start doing right now."