It was not characteristic of Brouillard – the Brouillard Grislow knew best – that he should suffer the purely technical talk of dams and reservoirs, bed-rock anchorages, and the latest word in concrete structural processes to languish and should drift into personal reminiscences over their first evening camp-fire in the Niquoia.

Because the personalities were gratefully varying the monotonies, and also because he had a jocose respect for the unusual, Grislow was careful not to discourage the drift. There had been a benumbing surfeit of the technical talk dating from the day and hour when the orders had come from Washington giving Brouillard his step up and directing him to advance with his squad of Reclamation-Service pioneers upon the new work in the western Timanyonis. But, apart from this, the reminiscences had an experimental value. Grislow's one unamiable leaning manifested itself in a zest for cleverly turning the hidden facets of the human polygon up to the light; and if the facets chose to turn themselves of their own accord, as in Brouillard's case, why, so much the better.

"As you were saying?" he prompted, stretching himself luxuriously upon the fragrant banking of freshly clipped spruce tips, with his feet to the blaze and his hands locked under his head. He felt that Brouillard was merely responding to the subtle influences of time, place, and encompassments and took no shame for being an analytical rather than a sympathetic listener. The hundred-odd men of the pioneer party, relaxing after the day-long march over the mountains, were smoking, yarning, or playing cards around the dozen or more camp-fires. The evening, with a half-grown moon silvering the inverted bowl of a firmament which seemed to shut down, lid-like, upon the mountain rim of the high-walled valley, was witchingly enchanting; and, to add the final touch, there was comradely isolation, Anson, Griffith, and Leshington, the three other members of the engineering staff, having gone to burn candles in the headquarters tent over blue-prints and field-notes.

"I was saying that the present-day world slant is sanely skeptical – as it should be," Brouillard went on at the end of the thoughtful pause. "Being modern and reasonably sophisticated, we can smile at the signs and omens of the ages that had to get along without laboratories and testing plants. Just the same, every man has his little atavistic streak, if you can hit upon it. For example, you may throw flip-flaps and call it rank superstition if you like, but I have never been able to get rid of the notion that birthdays are like the equinoxes – turning-points in the small, self-centred system which we call life."

"Poodle-dogs!" snorted the one whose attitude was both jocose and analytical, stuffing more of the spruce branches under his head to keep the pipe ashes from falling into his eyes.

"I know; being my peculiar weakness instead of your own, it's tommy-rot to you," Brouillard rejoined good-naturedly. "As I said a few minutes ago, I am only burbling to hear the sound of my own voice. But the bottoming fact remains. You give a screw twist to a child's mind, and if the mind of the man doesn't exhibit the same helical curve – "

"Suppose you climb down out of the high-browed altitudes and give it a plain, every-day name?" grumbled the staff authority on watersheds.

"It's casting pearls before swine, but you're a pretty good sort of swine, Grizzy. If you'll promise to keep your feet out of the trough, I'll tell you. Away back in the porringer period, in which we are all like the pin-feathered dicky-birds, open-mouthed for anything anybody may drop into us, some one fed me with the number seven."

"Succulent morsel!" chuckled Grislow. "Did it agree with you?"

Brouillard sat back from the fire and clasped his hands over his bent knees. He was of a type rare enough to be noteworthy in a race which has drawn so heavily upon the Anglo-Saxon and Teutonic stocks for its build and coloring: a well-knit figure of a man, rather under than over the normal stature, but bulging athletically in the loose-fitting khaki of the engineer; dark of skin, even where the sun had not burned its rich mahogany into the olive, and owning a face which, with the upcurled mustaches, the brooding black eyes, and the pure Gallic outline of brow and jaw, might have served as a model for a Vierge study of a fighting franc-tireur.

"I don't remember how early in the game the thing began," he resumed, ignoring Grislow's joking interruption, "but away back in the dimmest dawnings the number seven began to have a curious significance for me. From my earliest recollections things have been constantly associating themselves with seven or some multiple of it. You don't believe it, of course; but it is true."

"Which means that you have been sitting up and taking notice when the coincidences hit, and have forgotten the millions of times when they didn't," scoffed the listener.

"Probably," was the ready admission. "We all do that. But there is one set of 'coincidences,' as you call them, that can't be so easily turned down. Back in the pin-feather time that I mentioned somebody handed me a fact – the discovery of the physiologists about the waste and replacement that goes on in the human organism, bringing around a complete cellular change about once in every seven years. Are you asleep?"

"Not yet; go on," said the hydrographer.

"It was a long time ago, and I was only a little tad; but I surrounded the idea and took it in literally, in the sense of a sudden and sort of magical change coming at the end of each seven-year period and bound to occur at those particular fixed times. The notion stuck to me like a cockle-bur, and sometimes I wonder if it isn't still sticking."

"Bugs!" ranted Grislow, in good-natured ridicule, and Brouillard laughed.

"That is what I say to myself, Murray, every time the fatal period rolls around. And yet – "

"There isn't any 'and yet,'" cut in the scoffer derisively. "This is merely your night for being batty. 'Fatal period' – suffering humanity!"

"No, hold on: let me tell you, Murray – I'd like to get it out of my system if I can. Up to my seventh birthday I was a sickly child, puny and only about half alive. I recollect, as if it were only yesterday, how the neighbor women used to come in and condole with my mother, ignoring me, of course, as if I hadn't any ears. I can remember old Aunt Hetty Parsons saying, time and again: 'No, Mis' Brouillard; you'll never raise that boy the longest day you live!'"

"I'm waiting for the 'and yet,'" put in Grislow, sitting up to relight his pipe with a blazing splinter from the fire.

"It came – the change, I mean – when I was seven years old. That was the year of our removal to Vincennes from the country village where I was born. Since that time I haven't known what it means to be sick or even ailing."

"Bully old change!" applauded Grislow. "Is that all?"

"No. What the second period spent on my body it took out of my mind. I grew stouter and stronger every year and became more and more the stupidest blockhead that ever thumbed a school-book. I simply couldn't learn, Murray. My mother made excuses for me, as mothers will, but my father was in despair. He was an educated man, and I can imagine that my unconquerable doltishness went near to breaking his heart."

"You are safely over that stage of it now, at all events," said the hydrographer in exaggerated sarcasm. "Any man who can stare into the fire and think out fetching little imaginations like these you are handing me – "

"Sometimes I wish they were only imaginings, Grizzy. But let me finish. I was fourteen to a day when I squeezed through the final grammar grade; think of it – fourteen years old and still with the women teachers! I found out afterward that I got my dubiously given passport to the high school chiefly because my father was one of the best-known and best-loved men in the old home town. Perhaps it wasn't the magic seven that built me all over new that summer; perhaps it was only the change in schools and teachers. But from that year on, all the hard things were too easy. It was as if somebody or something had suddenly opened a closed door in my brain and let the daylight into all the dark corners at once."

Grislow sat up and finished for him.

"Yes; and since that time you have staved your way through the university, and butted into the Reclamation Service, and played skittles with every other man's chances of promotion until you have come out at the top of the heap in the Construction Division, all of which you're much too modest to brag about. But, say; we've skipped one of the seven-year flag-stations. What happened when you were twenty-one – or were you too busy just then chasing the elusive engineering degree to take notice?"

Brouillard was staring out over the loom of the dozen camp-fires – out and across the valley at the massive bulk of Mount Chigringo rising like a huge barrier dark to the sky-line save for a single pin-prick of yellow light fixing the position of a solitary miner's cabin half-way between the valley level and the summit. When he spoke again the hydrographer had been given time to shave another pipe charge of tobacco from his pocket plug and to fill and light the brier.

"When I was twenty-one my father died, and" – he stopped short and then went on in a tone which was more than half apologetic – "I don't mind telling you, Grislow; you're not the kind to pass it on where it would hurt. At twenty-one I was left with a back load that I am carrying to this good day; that I shall probably go on carrying through life."

Grislow walked around the fire, kicked two or three of the charred log ends into the blaze, and growled when the resulting smoke rose up to choke and blind him.

"Forget it, Victor," he said in blunt retraction. "I thought it was merely a little splashing match and I didn't mean to back you out into deep water. I know something about the load business myself; I'm trying to put a couple of kid brothers through college, right now."

"Are you?" said Brouillard half-absently; and then, as one who would not be selfishly indifferent: "That is fine. I wish I were going to have something as substantial as that to show for my wood sawing."

"Won't you?"

"Not in a thousand years, Murray."

"In less than a hundredth part of that time you'll be at the top of the Reclamation-Service pay-roll – won't that help out?"

"No; not appreciably."

Grislow gave it up at that and went back to the original contention.

"We're dodging the main issue," he said. "What is the active principle of your 'sevens' – or haven't you figured it out?"

"Change," was the prompt rejoinder; "always something different – radically different."

"And what started you off into the memory woods, particularly, to-night?"

"A small recurrence of the coincidences. It began with that hopelessly unreliable little clock that Anson persists in carrying around with him wherever he goes. While you were up on the hill cutting your spruce tips Anson pulled out and said he was going to unpack his camp kit. He went over to his tent and lighted up, and a few minutes afterward I heard the clock strike – seven. I looked at my watch and saw that it lacked a few minutes of eight, and the inference was that Anson had set the clock wrong, as he commonly does. Just as I was comfortably forgetting the significant reminder the clock went off again, striking slowly, as if the mechanism were nearly run down."

"Another seven?" queried Grislow, growing interested in spite of a keen desire to lapse into ridicule again.

"No; it struck four. I didn't imagine it, Murray; I counted: one – two – three – four."

"Well?" was the bantering comment. "You couldn't conjure an omen out of that, could you? You say there was a light in the tent – I suppose Anson was there tinkering with his little tin god of a timepiece. It's a habit of his."

"That was the natural inference; but I was curious enough to go and look. When I lifted the flap the tent was empty. The clock was ticking away on Anson's soap-box dressing-case, with a lighted candle beside it, and for a crazy half second I had a shock, Murray – the minute-hand was pointing to four and the hour-hand to seven!"

"Still I don't see the miraculous significance," said the hydrographer.

"Don't you? It was only another of the coincidences, of course. While I stood staring at the clock Anson came in with Griffith's tool kit. 'I've got to tinker her again,' he said. 'She's got so she keeps Pacific time with one hand and Eastern with the other.' Then I understood that he had been tinkering it and had merely gone over to Griffith's tent for the tools."

"Well," said Grislow again, "what of it? The clock struck seven, you say; but it also struck four."

Brouillard's smile tilted his curling mustaches to the sardonic angle.

"The combination was what called the turn, Grizzy. To-day happens to be my twenty-eighth birthday – the end of the fourth cycle of seven."

"By George!" ejaculated the hydrographer in mock perturbation, sitting up so suddenly that he dropped his pipe into the ashes of the fire. "In that case, according to what seems to be the well-established custom, something is due to fall in right now!"

"I have been looking for it all day," returned Brouillard calmly, "which is considerably more ridiculous than anything else I have owned to, you will say. Let it go at that. We'll talk about something real if you'd rather – that auxiliary reservoir supply from the Apache Basin, for example. Were the field-notes in when you left Washington?" And from the abrupt break, the technicalities came to their own again; were still holding the centre of the stage after the groups around the mess fires had melted away into the bunk shelters and tents, and the fires themselves had died down into chastened pools of incandescence edged each with its beach line of silvered ashes.

It was Murray Grislow who finally rang the curtain call on the prolonged shop-talk.

"Say, man! do you know that it is after ten o'clock?" he demanded, holding the face of his watch down to the glow of the dying embers. "You may sit here all night, if you like, but it's me for the blankets and a few lines of 'tired Nature's sweet restorer, balmy' – Now, what in the name of a guilty conscience is that?"

As it chanced, they were both facing toward the lower end of the valley when the quotation-breaking apparition flashed into view. In the deepest of the shadows at the mouth of the gorge, where the torrenting Niquoia straightened itself momentarily before entering upon its plunging race through the mountain barrier, a beam of white light flickered unsteadily for a fraction of a second. Then it became a luminous pencil to trace a zigzag line up the winding course of the river, across to the foot-hill spur where the camp of the Reclamation-Service vanguard was pitched, and so on around to the base of Chigringo. For certain other seconds it remained quiescent, glowing balefully like the eye of some fabled monster searching for its prey. Then it was gone.

Grislow's comment took the form of a half-startled exclamation.

"By Jove! wouldn't that give you a fit of the creepies? – this far from civilization and a dynamo?"

"It wasn't an electric," returned Brouillard thoughtfully, apparently taking Grislow's suggestion literally. "It was an acetylene."

"Supposing it was – what's the difference? Aren't we just as far from a carbide shop as we are from the dynamo? What are you calling it?"

"Your guess is as good as mine," was the half-absent reply. Brouillard was still staring fixedly at the distant gulf of blackness where the mysterious light had appeared and disappeared.

"Then I'll make it and go to bed," said the hydrographer, rising and stretching his arms over his head. "If it had come a couple of hours ago we should have called it the 'spot-light,' turned on to mark the end of your fourth act and the beginning, auspicious or otherwise, of the fifth. Maybe it is, anyway; maybe the property-man was asleep or drunk and forgot to turn it on at the spectacular instant. How will that do?"

Brouillard had got upon his feet and was buttoning his many-pocketed shooting-coat.

"It will do to put you into the Balaam saddle-beast class, Grizzy," he said, almost morosely. Then he added: "I'm going to take a little hike down yonder for investigative purposes. Want to come along?"

But the mapper of watersheds was yawning sleepily. "Not on your tintype," he refused. "I'm going to 'cork it orf in me 'ammick.' Wake me up when you come back and tell me what the fifth act is going to do to you. The more I think of it the more I'm convinced that it was the spot-light, a little overdue, after all." And he turned away chuckling.

It was only a short mile from the camp on the inward slopes of the eastern foot-hills to the mouth of the outlet gorge, across which Brouillard could already see, in mental prevision, the great gray wall of the projected Niquoia dam – his future work – curving majestically from the broken shoulder of Chigringo to the opposing steeps of Jack's Mountain. The half-grown moon, tilting now toward the sky-line of the western barrier, was leaving the canyon portal in deepest gloom. As Brouillard swung along he kept a watchful eye upon the gorge shadows, half expecting a return of the mysterious apparition. But when he finally reached the canyon portal and began to seek for the trail which roughly paralleled the left bank of the stream the mystery was still unexplained.

From its upper portal in the valley's throat to the point where the river debouches among the low sand-hills of the Buckskin Desert the canyon of the Niquoia measures little more than a mile as the bird flies, though its crookings through the barrier mountains fairly double the distance. Beginning as a broken ravine at the valley outlet, the gorge narrows in its lower third to a cliff-walled raceway for the torrent, and the trail, leaving the bank of the stream, climbs the forested slope of a boundary spur to descend abruptly to the water's edge again at the desert gateway, where the Niquoia, leaping joyously from the last of its many hamperings, becomes a placid river of the plain.

Picking his way judiciously because the trail was new to him, Brouillard came in due time to the descending path among the spruces and scrub-pines leading to the western outlook upon the desert swales and sand-hills. At the canyon portal, where the forest thinned away and left him standing at the head of the final descending plunge in the trail, he found himself looking down upon the explanation of the curious apparition.

None the less, what he saw was in itself rather inexplicable. In the first desert looping of the river a camp-fire of piñon knots was blazing cheerfully, and beside it, with a picnic hamper for a table, sat a supper party of three – two men and a woman – in enveloping dust-coats, and a third man in chauffeur leather serving the sitters. Back of the group, and with its detachable search-light missing, stood a huge touring-car to account for the picnic hamper, the dust-coats, the man in leather, and, doubtless, for the apparitional eye which had appeared and disappeared at the mouth of the upper gorge. Also it accounted, in a purely physical sense, for the presence of the picnickers, though the whim which had led them to cross the desolate Buckskin Desert for the dubious pleasure of making an all-night bivouac on its eastern edge was not so readily apparent.

Being himself a Bedouin of the desert, Brouillard's first impulse was hospitable. But when he remarked the ample proportions of the great touring-car and remembered the newness and rawness of his temporary camp he quickly decided that the young woman member of the party would probably fare better where she was.

This being the case, the young engineer saw no reason why he should intrude upon the group at the cheerful camp-fire. On the contrary, he began speedily to find good and sufficient reasons why he should not. That the real restraining motive was a sudden attack of desert shyness he would not have admitted. But the fact remained. Good red blood with its quickenings of courage and self-reliance, and a manful ability to do and dare, are the desert's gifts; but the penalty the desert exacts in return for them is evenly proportioned. Four years in the Reclamation Service had made the good-looking young chief of construction a man-queller of quality. But each year of isolation had done something toward weakening the social ties.

A loosened pebble turned the scale. When a bit of the coarse-grained sandstone of the trail rolled under Brouillard's foot and went clattering down to plunge into the stream the man in chauffeur leather reached for the search-light lantern and directed its beam upon the canyon portal. But by that time Brouillard had sought the shelter of the scrub-pines and was retracing his steps up the shoulder of the mountain.