"Nothing of itself, perhaps. But it explains all the fearful things I have seen with my own eyes. Two years ago, after the trouble with Mr.

Braithwaite, father seemed to change. He became bitterly vindictive against the Arcadia Company, and at times seemed to put his whole soul into the fight against it. Then the accidents began to happen, and--oh, I can't tell you the dreadful things I have seen, or the more dreadful ones I have suspected! I have watched him--followed him--when he did not suspect it. After dinner, the night you arrived, he left us all on the portico at Castle 'Cadia, telling me that he was obliged to come down here to the mine. Are you listening?"

"You needn't ask that: please go on."

"I thought it very strange; that he would let even a business errand take him away from us on our first evening; and so I--I made an excuse to the others and followed him. Breckenridge, I saw him throw the stone from the top of that cliff--the stone that came so near killing you or Mr. Bromley, or both of you."

There had been a time when he would have tried to convince her that she must doubt the evidence of her own senses; but now it was too late: that milestone had been pa.s.sed in the first broken sentence of her pitiful confession.

"There was no harm done, that time," he said, groping loyally for the available word of comforting.

"It was G.o.d's mercy," she a.s.serted. "But listen again: that other night, when Mr. Bromley was hurt ... After you had gone with the man who came for you, I hurried to find my father, meaning to ask him to send Otto in the little car to see if there was anything we could do. Aunt June said that father was lying down in the library: he was not there. I ran up-stairs. His coat and waistcoat were on the bed, and his mackintosh--the one he always wears when he goes out after sundown--was gone. After a little while he came in, hurriedly, secretly, and he would not believe me when I told him Mr. Bromley was hurt; he seemed to be sure it must be some one else. Then I knew. He had gone out to waylay you on your walk back to the camp, and by some means had mistaken Mr.

Bromley for you."

She was in the full flood-tide of the heart-broken confession now, and in sheer pity he tried to stop her.

"Let it all go," he counselled tenderly. "What is done, is done; and now that the work here is also done, there will be no more trouble for you."

"No; I must go on," she insisted. "Since others, who have no right to know, have found out, I must tell you."

"Others?" he queried.

"Yes: Mr. Wingfield, for one. Unlike you, he has not tried to be charitable. He believes----"

"He doesn't love you as I do," Ballard interrupted quickly.

"He doesn't love me at all--that way; it's Dosia. Hadn't you suspected?

That was why he joined Aunt Janet's party--to be with Dosia."

"Thus vanishes the final shadow: there is nothing to come between us now," he exulted; and his unhurt arm drew her close.

"Don't!" she shuddered, shrinking away from him. "That is the bitterest drop in the cup of misery. You refuse to think of the awful heritage I should bring you; but I think of it--day and night. When your telegram came from Boston to Mr. La.s.sley at New York, I was going with the La.s.sleys--not to Norway, but to Paris, to try to persuade Doctor Perard, the great alienist, to come over and be our guest at Castle 'Cadia. It seemed to be the only remaining hope. But when you telegraphed your changed plans, I knew I couldn't go; I knew I must come home. And in spite of all, he has tried three times to kill you. You know he must be insane; tell me you know it," she pleaded.

"Since it lifts a burden too heavy to be borne, I am very willing to believe it," he rejoined gravely. "I understand quite fully now. And it makes no difference--between us, I mean. You must not let it make a difference. Let the past be past, and let us come back to the present.

Where is your father now?"

"After dinner he went with Mr. Wingfield and Otto to the upper canyon.

There is a breakwater at the canyon portal which they hoped might save the power-house and laboratory from being undermined by the river, and they were going to strengthen it with bags of sand. I was afraid of what might come afterward--that you might be here alone and unsuspecting. So I persuaded Cousin Janet and the others to make up the car-party."

From where they were sitting at the derrick's foot, the great boom leaned out like a giant's arm uplifted above the canyon lake. With the moon sweeping toward the zenith, the shadow of the huge iron beam was clearly cut on the surface of the water. Ballard's eye had been mechanically marking the line of shadow and its changing position as the water level rose in the Elbow.

"The reservoir is filling a great deal faster than I supposed it would,"

he said, bearing his companion resolutely away from the painful things.

"There have been storms on the main range all day," was the reply.

"Father has a series of electrical signal stations all along the upper canyon. He said at the dinner-table that the rise to-night promises to be greater than any we have ever seen."

Ballard came alive upon the professional side of him with a sudden quickening of the workaday faculties. With the utmost confidence in that part of the great retaining-wall for which he was personally responsible--the superstructure--he had still been hoping that the huge reservoir lake would fill normally; that the dam would not be called upon to take its enormous stresses like an engine starting under a full load. It was for this reason that he had been glad to time the closing of the spillway in August, when the flow of the river was at its minimum. But fate, the persistent ill-fortune which had dogged the Arcadian enterprise from the beginning, seemed to be gathering its forces for a final blow.

"Cloud-bursts?" he questioned. "Are they frequent in the head basin of the Boiling Water?"

"Not frequent, but very terrible when they do occur. I have seen the Elbow toss its spray to the top of this cliff--once, when I was quite small; and on that day the lower part of our valley was, for a few hours, a vast flood lake."

"Was that before or after the opening of your father's mine over yonder?" queried Ballard.

"It was after. I suppose the mine was flooded, and I remember there was no work done in it for a long time. When it was reopened, a few years ago, father had that immense bulkhead and heavy, water-tight door put in to guard against another possible flood."

Ballard made the sign of comprehension. Here was one of the mysteries very naturally accounted for. The bulkhead and iron-bound door of the zirconium mine were, indeed, fortifications; but the enemy to be repulsed was nature--not man.

"And the electric signal service system in the upper canyon is a part of the defence for the mine?" he predicated.

"Yes. It has served on two or three occasions to give timely warning so that the miners could come up and seal the door in the bulkhead. But it has been a long time since a cloud-burst flood has risen high enough in the Elbow to threaten the mine."

Silence supervened; the silence of the flooding moonlight, the stark hills and the gently lapping waters. Ballard's brain was busy with the newly developed responsibilities. There was a little s.p.a.ce for action, but what could be done? In all probability the newly completed dam was about to be subjected to the supreme test, violently and suddenly applied. The alternative was to open the spillway gate, using the cut-off tunnel as a sort of safety-valve when the coming flood water should reach the Elbow.

But there were an objection and an obstacle. Now that he knew the condition of the honeycombed tunnel, Ballard hesitated to make it the raceway for the tremendously augmented torrent. And for the obstacle there was a mechanical difficulty: with the weight of the deepening lake upon it, the stop-gate could be raised only by the power-screws; and the fires were out in the engine that must furnish the power.

The Kentuckian was afoot and alert when he said: "You know the probabilities better than any of us: how much time have we before these flood tides will come down?"

She had risen to stand with him, steadying herself by the hook of the derrick-fall. "I don't know," she began; and at that instant a great slice of the zirconium mine dump slid off and settled into the eddying depths with a splash.

"It is nothing but a few more cubic yards of the waste," he said, when she started and caught her breath with a little gasp.

"Not that--but the door!" she faltered, pointing across the chasm. "It was shut when we came out here--I am positive!"

The heavy, iron-studded door in the bulkhead was open now, at all events, as they could both plainly see; and presently she went on in a frightened whisper: "Look! there is something moving--this side of the door--among the loose timbers!"

The moving object defined itself clearly in the next half-minute; for the two at the derrick-heel, and for another--young Blacklock, who was crouching behind his rejected thorough-stone directly opposite the mine entrance. It took shape as the figure of a man, slouch-hatted and m.u.f.fled in a long coat, creeping on hands and knees toward the farther dam-head; creeping by inches and dragging what appeared to be a six-foot length of iron pipe. The king's daughter spoke again, and this time her whisper was full of sharp agony.

"_Breckenridge!_ it is my father--just as I have seen him before! That thing he is dragging after him: isn't it a--merciful Heaven! he is going to blow up the dam! Oh, for pity's sake can't you think of some way to stop him?"

There are crises when the mind, acting like a piece of automatic machinery, flies from suggestion to conclusion with such facile rapidity that all the intermediate steps are slurred and effaced. Ballard marked the inching advance, realised its object and saw that he would not have time to intervene by crossing the dam, all in the same instant. Another click of the mental mechanism and the alternative suggested itself, was grasped, weighed, accepted and trans.m.u.ted into action.

It was a gymnast's trick, neatly done. The looped-up derrick-fall was a double wire cable, running through a heavy iron sheave which carried the hook and grappling chains. Released from its rope lashings at the mast-heel, it would swing out and across the canyon like a monster pendulum. Ballard forgot his bandaged arm when he laid hold of the sheave-hook and slashed at the yarn seizings with his pocket-knife; was still oblivious to it when the released pendulum surged free and swept him out over the chasm.

XXIII

DEEP UNTO DEEP

Mechanically as such things are done, Ballard remembered afterward that he was keenly alive to all that was pa.s.sing. He heard Elsa's half-stifled cry of horror, Blacklock's shout of encouragement from some point higher up on the mesa, and mingled with these the quick _pad-pad_ of footfalls as of men running. In mid-air he had a glimpse of the running men; two of them racing down the canyon on the side toward which his swinging bridge was projecting him. Then the derrick-fall swept him on, reached the extreme of its arc, and at the reversing pause he dropped, all fingers to clutch and tensely strung muscles to hold, fairly upon the crouching man in the m.u.f.fling rain-coat.

For Blacklock, charging in upon the battle-field by way of the dam, the happenings of the next half-minute resolved themselves into a fierce hand-to-hand struggle between the two men for the possession of the piece of iron pipe. At the pendulum-swinging instant, the collegian had seen the sputtering flare of a match in the dynamiter's hands; and in the dash across the dam he had a whiff of burning gunpowder.

When the two rose up out of the dust of the grapple, Ballard was the victor. He had wrested the ignited pipe-bomb from his antagonist, and turning quickly he hurled it in a mighty javelin-cast far up the Elbow.

There was a splash, a smothered explosion, and a geyser-like column of water shot up from the plunging-point, spouting high to fall in sheets of silver spray upon the two upcoming runners who were alertly springing from foothold to foothold across the dissolving mine dump.