"latitude 27° 42′ 10′′, longitude 128° 7′ 11′′." it was noon three days after leaving thirsty spring, as their last strangely-found well had been designated, and bob read aloud these observations as he noted them down in his log-book. they had reached the vicinity of bentley's last camp, and all eyes had been alert for the melancholy symbols of the ill-fated expedition. away to the east the country extended back in a series of rugged "blows" until they suddenly merged into apparent nothingness; a swelling, white haze obscured the true horizon in this direction, but north and south well-wooded grassy plains stretched into the dim distance. the uttermost edge of the desert seemed to have been reached at last.

"ay, it was just about here that the camel broke away," said mackay, musingly, "and over there"—he pointed to the east—"lies the mountain."

"it must be a terrible long way over there, mac," commented emu bill, "for we should see it 'bout forty miles off if it is any size, an' you said it was a whopper."

mackay looked puzzled; certainly no mountain was visible at this period.

"it must be there," he reiterated grimly.

[pg 268]

bob, too, was much exercised over the prolonged absence of the desert sentinel; it had figured so much in all their calculations that it had, indeed, been the initial quest of the expedition.

"there's an extraordinary heat haze rising up straight ahead," said he. "perhaps it hides that shadowy mountain."

"it's there right enough," said mackay, again. "i mind well that i didna see it until i was right up against it."

"there's something mighty uncanny about this place," grunted never never dave, who had been gazing around suspiciously.

a gentle zephyr breeze wafted towards them from the obscuring mists, and they sniffed the air wonderingly.

"blow me tight, boys," muttered emu bill, "we has struck old jimmy squarefoot's country."

"that are a fact," concurred never never dave, solemnly; "we has come a bit too far on this trip. no wonder poor ole bentley didn't get back."

"why, what is wrong?" asked jack, in some alarm.

"what is wrong?" echoed never never. "why, we must be near hades, my lad; don't you smell it?"

a strong odour of a pungent, sulphurous nature assuredly filled the air. mackay was equally mystified with the others, though he did not give expression to his thoughts. he was trying to recall to the minutest incident the happenings of over a year ago in the same district.

"i distinctly saw their tracks," he repeated, half to himself, "and the bones——"

[pg 269]

"but there ain't no bones now," interrupted emu bill. "there's some curious mystery about this here place, there is."

a cry from the shadow, who had gone exploring on his own account some distance off, drew their attention. it was plain that he had discovered something important, for he semaphored to them excitedly as they looked. silently they obeyed his summons, and in a few minutes were gazing at the poor relics of the last expedition, where they lay half covered in the sand.

there they were beyond a doubt, a mass of bleaching bones. reverently they uncovered their heads, then mackay knelt down by the sad litter, and great, dry sobs shook his breast. his companions turned away with heavy eyes, all but bob, who remained to comfort the grief-stricken man.

"we may at least bury the remains," he said sadly, "and i think we might put up a small mark over the spot. there are lots of trees about which we could cut down."

mackay looked at him kindly. "not yet, bob, not yet," he muttered hoarsely; "not till i have squared accounts with the wretches who committed this crime. these poor fellows here were murdered after daring the dangers o' the desert; their last mortal remains have awaited my coming here on the surface o' the sweltering sands, and they cry to me for vengeance—and vengeance they shall have before i cover them from the light o' a just heaven." he rose with forced calm and linked his arm in bob's. "you shall help me, bob," he said earnestly; "you of all people have a reason——"

he ceased abruptly as emu bill appeared once more.[pg 270] the tall bushman was apparently much moved, though he strove to hide his sorrow.

"i has just been talkin' to never never," he began, in an even voice, "an' we has come to the conclusion that we'll go an' wipe out some o' them skunks who did this. i reckon we'll feel better after it."

mackay smiled faintly. "i believe we are near the end o' our search for the hidden treasure o' the never never," he said quietly. "the invisible mountain must mark the entrance to the land we are seeking, but we may have many a struggle before we triumph, but each difficulty overcome will bring us nearer our goal. let us move on once more, bill; i must see the other side o' the mountain——"

"an' nary one o' us is goin' back on you," said emu bill, with a grim laugh. "wherever that there perfume comes from, i reckon never never an' me will see the end o' the journey."

they retraced their way to the camels, and in a short time were forcing a trail on into the seething mists. and now the stumbling camel-train experienced great difficulty in negotiating the many dry ravines that lay in their course, and they climbed over the basaltic bluffs which now and again reared their heads above the boulder-strewn expanse, only with the extremest effort. the sun beat down pitilessly on the wayfarers, and here the heat was, indeed, overpowering; it seemed to rise in long, pulsating swells from the bare rocks and hang in a filmy cloud of vapour, through which the eye could see but vaguely, as in a dream-picture. on, on, the pioneers struggled, and as they proceeded, the strange, sulphurous odour became more and more perceptible, until it assailed the nostrils in sharp,[pg 271] burning breaths. yet still the vision ahead was clouded by dense white vapours, and the horizon remained obscured. then suddenly a curious thing happened: the shrouding curtain in the near distance lifted up like a giant screen in a theatre, and through the mists of dispelling ether a dark towering height loomed up vividly.

"the mountain! the mountain!" cried jack; and truly it was a mountain, and a mountain of so precipitous and forbidding an aspect that it looked like an immense black wall rising into the sky.

"that is just how i ran up against it before," said mackay, calmly. "it appeared all at once, and i wondered why i didna see it earlier."

"well, this beats me," growled emu bill. "an' why in all the world didn't we see such a colossal monument before? we oughter have sighted that there tower o' babel at least two days back."

even as he spoke a great white mask rose from the base of the towering elevation, and in an instant the mighty landmark had vanished from their view.

"i reckon we has had a sight o' ole jimmy squarefoot's furnace," remarked never never dave, mysteriously. "an' don't it smell strong?"

"it jest howls," groaned emu bill, gasping hard.

mackay kept an unmoved silence. he apparently had no intention of being surprised at anything; but bob somewhat eased the minds of the twain by endeavouring to explain the phenomenon they had witnessed.

"the covering haze is nothing but steam," said he. "i think the mountain must be volcanic."

mackay shook his head. "i shouldna wonder if it is an extinct volcano," he said; "but there was no[pg 272] lava flow that i remember, and it disappeared just the same."

notwithstanding the odd happenings during the last few minutes, the camels were not permitted to slacken their pace. each and all of the party had determined to probe the mystery to the fullest, and the solution was soon forthcoming. as they forced their way into the densest depths of the ghost-like curtain, they became quickly aware of a gurgling, boiling sound almost at their feet. bob's keen ears were the first to catch the unwonted echoes; but before he could speak a greenish-yellow cloud rolled before his eyes, and he staggered back, choking wildly.

"ease off, boys," spoke mackay. "we must scout around an' investigate before we go further."

the whole party, camels and all, were now enveloped in the wreathing smoke-columns, and the sky was hidden from sight. blindly bob made a few steps forward, keeping well to the right of the unseen caldron, which now bubbled and foamed spasmodically. the shadow followed, stumbling and gasping, and within a minute the two found themselves in a clear and untainted atmosphere, and but a yard or so from the base of the gloomy mountain. loudly they shouted to their companions, and soon the spectral forms of the camels hove into view, with mackay and jack treading cautiously at their head. but where were emu bill and never never dave? they seemed to have vanished completely.

"they were alongside jack an' me a minute ago," said mackay, gazing wonderingly around.

"i reckon i'll go back an' see if they've stopped to look at the scenery," grunted the shadow; and he made a dash into the heavy fumes once more.

[pg 273]

the three who waited by the camels heard a startled cry, followed by a faint splash, then all was silent. hastily mackay seized a camel pack-rope, and would have rushed off after him, but bob interfered.

"i think i can guess where to find them," he said. "let me go."

with reluctance mackay saw him depart; but before bob had entered the chaos the swelling mass rose before him, disclosing in his track a broad, pit-like cavity. hurriedly he strode to the edge of the caldron; but ere he reached it the shadow climbed out of its seething depths wet and dripping, and saying strange things to himself. immediately behind him never never dave's head popped up, and an eloquent flow of language was let loose upon the air. lastly, emu bill scrambled into the open. he looked savagely around for a moment, until he caught sight of the shadow, and his wrath overflowed in a torrent of abuse. all three were bedraggled enough looking specimens; but the last arrivals were considerably worse off than the shadow in that respect—their hair was covered with a greenish scum, which spread down over their faces and almost blinded them.

"it was all that wretched young shadow's fault!" roared emu bill.

"but you were there first, bill," remonstrated mackay, laughingly.

"of course we were. we went plump into the filthy boilers; but we got a good grip o' the sides, and were sliding out quick an' lively, when, blow me! if that howlin' scarecrow didn't bounce down on top o' us, an' sent us swimmin' like tadpoles to the bottom. ugh!"

but their indignation quelled speedily when they learnt[pg 274] how excellent had been the intentions of the much-maligned youth.

"it must be a hot spring," said bob.

"and there are more of them," cried jack. "see, they are scattered all round the foot of the mountain."

"i reckon it is hot, right enough," grumbled emu bill. "i'm just 'bout turned into a salamander, i is."

as jack had noticed, quite a number of similar indentations formed a line right along the base of the mountain, and in each yawning crater examined, a greenish-yellow fluid bubbled tempestuously. high overhead the smoke-wreaths dissembled into thin air, and for a brief space all was beautifully clear. then a dull rumble like the mutterings of subdued thunder was heard, and immediately snowy puffs of smoke issued from the strange cavities. the denser fumes rapidly spread along the ground like a turbulent, foaming sea; then the whole seemed gradually to rise upwards and suspend as a filmy pall before the face of the mountain. yet, strangely enough, the noxious odours were now almost absent.

"ay, it's vera marvellous," said mackay, with a sigh. "so does nature protect her treasure-houses."

"it's a wonder you managed to get through without accident when you came," bob observed thoughtfully. "but, then, it's possible the line was clear when you passed."

"a breeze of wind would have lifted that fog," hazarded jack. "i should think that on some days the clouds would not be nearly so constant nor so thick."

"you're possibly right, jack," mused mackay, looking upwards. "see how the smoke curls in to the west now."

they all followed his gaze, and, surely enough, the mists[pg 275] appeared to bend over before a powerful air current and break off into numberless flying patches of lambent spray. assuredly, a fairly strong blast must be blowing on the mountain summit, though all was serene and unmoved below. they now bethought themselves of having an inspection of the wonderful elevation, which they had reached after so much weary striving. there it stood, gaunt and bare, precipitous in outline, and rising almost sheer to a height of over eight hundred feet, and as far as the eye could reach in either direction along the base, the same grim barrier appeared, but it curved in almost imperceptibly at each limit of observation.

"the monument might stretch across into queensland," said emu bill, "if we tried to follow it round. i vote we does a scramble over the top."

"i tried that before, bill," answered mackay, "but i'm going to try it again. only we'll look for the easiest side before we start."

"but what about the camels?" asked jack. "we can never get them over it."

"an' we've got to remember that there's an all-fired quantity o' bloodthirsty niggers about," said never never dave.

"suppose we hobble them out on the other side of the smoke," suggested bob. "if the blacks stay beyond the mountain they couldn't very well see them so close in, and the camels are too tired to wander much."

"it's a risk, bob," said mackay; "but the whole journey has been a risk, an' it's the best we can do. we can keep an eye on them from the top—if we get there."

"an' our rifles can speak for us from there well[pg 276] enough," laughed emu bill; "an' there's one howlin' satisfaction about it, there's nary spear could reach us."

and so it was arranged; the four tired beasts were unloaded, the bell was unstrapped from misery's neck, and the shadow led them out to the plains, man?uvring most carefully in his passage between the bubbling caldrons. in a few minutes he returned, with a somewhat anxious visage.

"i is pretty certain i saw a nig on the top o' the hill when i was out back a bit," he announced.

"on the top o' the hill?" cried emu bill, incredulously. "well, if they don't pop too many spears at us, i don't mind if they stay there until we get up."

"but you couldn't see anything through the haze, shad," said bob.

"i just did. the top o' the concern was shining strong in the sun, an' i got a sight o' a big nigger dressed like a corroborree mourner standin' looking' at me."

it was quite possible that the shadow's information was correct, for the fine haze in the upper air would barely have obscured the bold ridge of the mountain summit, especially with the sun's rays beating strong upon it. yet it was evident that the young bushman's statement was received with considerable unbelief.

"it's been a hallucination, shad," laughed jack.

it was already late in the afternoon, and it would have been useless to attempt the climb that night, so a tour of investigation was made in order to discover the least impregnable aspect of the frowning barrier, and as the little party moved along they carried their rifles ready for immediate action in case of a sudden alarm. but not a sign of natives was observed, and they tramped mile after[pg 277] mile over the jagged rocky débris lining the base of the mountain without once noting an easier place of ascent than that which they had first gazed upon. not a trace of vegetation showed on the steep declivity; the bare rocks scintillated in the last rays of the setting sun, and showed up barren and forbidding. here and there deep clefts appeared, striating the gloomy formation, and cutting deep into the heart of the mountain. it was one of these that drew an exclamation from mackay.

"that looks vera like the cap o' a gold-bearing lode showing at the bottom o' the gully," he cried. he crept carefully into the yawning crevice, and broke off a piece of the supposed auriferous stone with the iron heel of his boot. "decomposed diorite," he announced, "and showing gold all over. i do believe the whole mountain is just a mass of gold lodes an' leaders."

"well, i'm blest," murmured emu bill, "if that don't beat everything——"

"but we can't carry the hillock away," said jack, hurriedly.

the difficulties of transport had at once appeared to his practical mind, and his words acted as a restraining tonic on the exhilarating spirits of the others.

"you're right there, jack," agreed mackay, with a smile, "but if we get plenty of water on the other side, we could very soon get machinery out here; an' i've a firm idea that our golden land o' promise lies just beyond this barrier." he tapped the rocky surface with his hand meditatively. "and more than that," he continued, with rising excitement, "i believe we'll find rubies and diamonds as well. i mind we picked up some rubies in the gullies around the last camp when i was here before. at least,[pg 278] phil, the geologist, said they were rubies, an' i'd back his knowledge in that direction against any man's. he said they had been shed from some mountain or other, but, of course, we hadna seen the mountain at this time; and poor phil never did see it, either."

they commenced to retrace their steps, for the night was fast closing in, and as they walked along, bob stooped down occasionally to pick up pebbles from the silted driftage at his feet, and unobtrusively placed them in his pocket for future inspection. they had almost reached the place where they had unloaded the camels, when the shadow shouted out triumphantly—

"look, boys! i reckon there ain't no mistake about that nigger, is there?"

he was gazing at the ridge forming the summit of the mountain, and looking up, bob saw a tall, dishevelled figure standing against the sky-line and waving his arms energetically.

"by gum, he is wild!" laughed emu bill; "an' what a dandy outfit he's got; why, the beggar's got a 'possum blanket over him."

he raised his rifle mechanically, but mackay had already levelled his piece at the silhouetted form.

"please don't shoot," pleaded bob, staying his hand. "it almost seems like murder to kill a man like that."

mackay lowered his weapon with a groan, and bob, looking upwards once more, was astounded to see the object of his commiseration extending his hands as if in benediction. he stood thus for a moment, then, with a despairing gesture, pointed towards the western desert.

"i'm glad i didna shoot," said mackay; "that's the[pg 279] most wonderful savage i've seen. he even tried to warn us not to come further."

"that was out o' gratitood for us not shootin'," laughed emu bill; "but, blow me, i can't shoot a nig when he hasn't a spear or weapon o' some sort in his hand."

when they looked again, the strange aboriginal was gone.

the spirits of the little party were unusually cheerful that night, as they sat around their camp-fire and talked eagerly over their prospects on the morrow. their objective had been reached at last, the toil and stress of the dreary journey was over, the reward—and of reward they all seemed well assured—was now about to be theirs.

"i reckon i'll give ye a hymn o' praise on the orchestra," remarked the shadow, pulling his ear-shattering instrument from the pocket where it had lain silent since the finding of fortunate spring.

"if ye does," threatened emu bill, "i'll dump ye in that there smelling solution right over the head."

"hang it, bill," complained the unappreciated musician, "i ain't quite dry yet, as it is. couldn't ye think o' some happier kind o' return for my professional services?"

"anyhow," consoled jack, "it wouldn't do to let the niggers know we were about; they might come for us when we were helplessly enslaved with your melody."

the shadow grinned. "right o," said he; "music is off."

but mackay had not seemed at all unwilling to encourage the youth's suggestion.

"the blacks should ken we are about by this time," he observed lightly; "but there are six good rifles in this[pg 280] camp, an' we might as well encourage them to come out now as at any other time. there's going to be a good moon up to-night."

"you might give us a tootle on the flute," said never never dave; "i hasn't heard ye play since we left golden flat."

"let us have 'the muskittie's lament,'" urged the shadow; "i is just dyin' to stretch my voice a bit."

"no, shadow; though you are a budding sims reeves, i can't sympathize wi' you enough just now to listen to you singing. i must even deny you the pleasure o' hearing me warble the old familiar tune to-night, for i'm no' in the mood for waxing extravagantly joyous. but seein' we've reached the deceivin' mountain at last, and without mishap, i'll gie ye a blaw on the flute, if only to make this night something different from other nights."

jack fetched the flute with alacrity, and then seated himself beside bob, and soon the little group were listening in hushed silence to the pensive strains of one of balfe's melodies. when it was finished, the man of many moods paused for a moment, and his eyes roamed instinctively back towards the desert, and though the smoky cloud still intervened, bob guessed at once that he was again filled with swelling memories of the past.

"let us have something lively, mac," said emu bill, "something that will make us forget them pestiferous niggers for a bit."

"i can't do it, bill," came the husky response; "not here, not to-night." then he lifted the flute once more. "i'll play you one o' bentley's favourite hymns," he said gravely. "well do i mind we used a' to sing it whiles when we were on the march."

[pg 281]

softly into the night rose the notes; they lingered by each deep crevasse on the mountain side, and echoed back from the rocky steeps. unspeakably entrancing was the effect. the musician himself seemed lost in the wonderful sounds he created, and his hearers, after listening in mute attention for some time, by a common impulse joined in with the words, familiar to them all—

"lead, kindly light,...

lead thou me on."

and as the rough voices swelled upwards, a weird answering chorus floated back to them from the summit of the mountain, and lo! several dark forms appeared outlined against the starry sky. emu bill ceased his vocal exercises at once, and squirmed about uneasily until the flute stopped.

"say, mates," said he, anxiously; "i hope it ain't no corroborree song they is singin'."

mackay glanced upwards, then hastily grasped his rifle, but the vague voices in the air broke afresh upon his ears just as he was about to pull the trigger, and he laid the deadly weapon down with a shudder.

"they are actually mimicking that bonnie hymn," he said nervously. "i—i haven't the heart to shoot——"

"and aren't their voices almost musical!" cried jack, whose ear was keenly attuned to melody. "they make a very much better attempt than our corroborree savages did about a week ago; their voices were simply hideous."

"the aborigines are born mimics, jack," answered mackay; "but, as you say, their song is usually enough to drive a man to drink—providin' he can get it. still there may be a different sort o' savage in this mysterious[pg 282] country. if the land itself is better, it would influence the people, and who knows maybe they have acquired some accomplishments unknown to their brethren on the flats."

"i can't make them out at all," said bob, quietly. "everything seems so unreal, so—so uncanny about here, and these niggers singing that hymn have given me the creeps."

"let me have one go at 'the muskittie's lament,'" pleaded the shadow. "i reckon it would bust them up to mimic that high note——"

"you leave that long-suffering muskittie alone," said mackay. "we'll bust them up wi' something more solid in the morning. i'll climb that mountain or go under trying."

conversation somewhat flagged after that. the events of the day had all been so strange and inexplicable; the lure of the mountain was becoming oppressively potent, and each of the staunch little band was filled with his own secret convictions regarding what might lie beyond.

"better turn into your blankets, boys," said mackay, at length. "you'll need all your energies in the morning. i'm going to keep watch and see that nothing happens while you sleep. i'm not going to risk another wipe out in this quarter."

"you ain't goin' to do sentry go on your own," spoke never never dave. "i reckon i'll take my turn."

"an' me, of course!" cried emu bill.

"and ain't the poor, low-down shadow any good?" complained that individual, pathetically. "let me do a prance round, boss. i ain't a bit sleepy."

"let jack and me take it for the first night," said bob, quietly.

[pg 283]

mackay laughed. "i know you are all vera willing, my lads, but the first night is my care; i'll ask bob, who is next in responsibility, to take part o' the watch. jack and the shadow will be on duty to-morrow night, and you, bill and never never, can take the next;" which equable arrangement appeared to suit every one.

then bob arose, rifle in hand, and stepped forward.

"no, no, bob; not yet," said mackay. "i'll call you in three or four hours to take a spell. lie down and sleep for a bit, my lad."

but bob was obdurate. "you've been wearing yourself out these last few days," he said simply. "you can surely trust me to fill your place for the first half of the night, at least. perhaps i may not need to call you, for i know i couldn't sleep if i tried. my brain is buzzing with odd ideas, which would be bound to keep me awake."

the elder man hesitated for a moment, then gave in. "but promise to call me at one o'clock, bob," he said, "otherwise i'll stay up with you;" and bob promised.

a few minutes and a row of sleeping figures lay outstretched around the fire. bob tightened up his cartridge-belt, pulled up the heads of several cartridges so that they might be easily extracted in an emergency, examined the magazine of his gun, and closed the breech gently, bringing the trigger to full cock. then he waited, motionless as a statue, beside the huddled forms of his comrades, with rifle upraised, and every nerve strung at highest tension. well he knew that danger threatened; he felt it in the air; an ominous calm prevailed; how soon would it be broken by the savage yells of the guardians of the mountain? bob gripped his rifle the tighter, and his[pg 284] eyes scanned the near distance critically, then roamed aloft to the now deserted mountain summit. a slight sound startled him, and his finger closed gently on the trigger of his weapon, but it was only mackay tossing restlessly in his blanket. bob looked pityingly at the sleepless form, and at that moment mackay beckoned him.

"i canna get it out o' my mind," he whispered, "that when i followed the tracks o' the blacks, they led right into the mountain an' no' round about it, an' it beats me to know how they managed to climb over so quickly. keep a careful watch, bob; keep a careful watch."

bob nodded silently and returned to his position. he had unconsciously shared mackay's fears before they had been spoken. since he first saw the mysterious mount he had marvelled how it had been scaled, and how descents had been accomplished.

the southern cross slowly sank to rest, and the edge of the great bear constellation peeped above the northern horizon. yet still the watcher stood erect at his post, and the camp slumbered.