IT was agreed that the inhabitants of the cottage must keep more on their guard than ever. The threats of old Silfax were too serious to be disregarded. It was only too possible that he possessed some terrible means by which the whole of Aberfoyle might be annihilated.

Armed sentinels were posted at the various entrances to the mine, with orders to keep strict watch day and night. Any stranger entering the mine was brought before James Starr, that he might give an account of himself. There being no fear of treason among the inhabitants of Coal Town, the threatened danger to the subterranean colony was made known to them. Nell was informed of all the precautions taken, and became more tranquil, although she was not free from uneasiness. Harry’s determination to follow her wherever she went compelled her to promise not to escape from her friends.

During the week preceding the wedding, no accident whatever occurred in Aberfoyle. The system of watching was carefully maintained, but the miners began to recover from the panic, which had seriously interrupted the work of excavation. James Starr continued to look out for Silfax. The old man having vindictively declared that Nell should never marry Simon’s son, it was natural to suppose that he would not hesitate to commit any violent deed which would hinder their union.

The examination of the mine was carried on minutely. Every passage and gallery was searched, up to those higher ranges which opened out among the ruins of Dundonald Castle. It was rightly supposed that through this old building Silfax passed out to obtain what was needful for the support of his miserable existence (which he must have done, either by purchasing or thieving).

As to the “fire-maidens,” James Starr began to think that appearance must have been produced by some jet of fire-damp gas which, issuing from that part of the pit, could be lighted by Silfax. He was not far wrong; but all search for proof of this was fruitless, and the continued strain of anxiety in this perpetual effort to detect a malignant and invisible being rendered the engineer—outwardly calm—an unhappy man.

As the wedding-day approached, his dread of some catastrophe increased, and he could not but speak of it to the old overman, whose uneasiness soon more than equaled his own. At length the day came. Silfax had given no token of existence.

By daybreak the entire population of Coal Town was astir. Work was suspended; overseers and workmen alike desired to do honor to Simon Ford and his son. They all felt they owed a large debt of gratitude to these bold and persevering men, by whose means the mine had been restored to its former prosperity. The ceremony was to take place at eleven o’clock, in St. Giles’s chapel, which stood on the shores of Loch Malcolm.

At the appointed time, Harry left the cottage, supporting his mother on his arm, while Simon led the bride. Following them came Starr, the engineer, composed in manner, but in reality nerved to expect the worst, and Jack Ryan, stepping superb in full Highland piper’s costume. Then came the other mining engineers, the principal people of Coal Town, the friends and comrades of the old overman—every member of this great family of miners forming the population of New Aberfoyle.

In the outer world, the day was one of the hottest of the month of August, peculiarly oppressive in northern countries. The sultry air penetrated the depths of the coal mine, and elevated the temperature. The air which entered through the ventilating shafts, and the great tunnel of Loch Malcolm, was charged with electricity, and the barometer, it was afterwards remarked, had fallen in a remarkable manner. There was, indeed, every indication that a storm might burst forth beneath the rocky vault which formed the roof of the enormous crypt of the very mine itself.

But the inhabitants were not at that moment troubling themselves about the chances of atmospheric disturbance above ground. Everybody, as a matter of course, had put on his best clothes for the occasion. Madge was dressed in the fashion of days gone by, wearing the “toy” and the “rokelay,” or Tartan plaid, of matrons of the olden time, old Simon wore a coat of which Bailie Nicol Jarvie himself would have approved.

Nell had resolved to show nothing of her mental agitation; she forbade her heart to beat, or her inward terrors to betray themselves, and the brave girl appeared before all with a calm and collected aspect. She had declined every ornament of dress, and the very simplicity of her attire added to the charming elegance of her appearance. Her hair was bound with the “snood,” the usual head-dress of Scottish maidens.

All proceeded towards St. Giles’s chapel, which had been handsomely decorated for the occasion.

The electric discs of light which illuminated Coal Town blazed like so many suns. A luminous atmosphere pervaded New Aberfoyle. In the chapel, electric lamps shed a glow over the stained-glass windows, which shone like fiery kaleidoscopes. At the porch of the chapel the minister awaited the arrival of the wedding party.

It approached, after having passed in stately procession along the shore of Loch Malcolm. Then the tones of the organ were heard, and, preceded by the minister, the group advanced into the chapel. The Divine blessing was first invoked on all present. Then Harry and Nell remained alone before the minister, who, holding the sacred book in his hand, proceeded to say, “Harry, will you take Nell to be your wife, and will you promise to love her always?”

“I promise,” answered the young man in a firm and steady voice.

“And you, Nell,” continued the minister, “will you take Harry to be your husband, and—”

Before he could finish the sentence, a prodigious noise resounded from without. One of the enormous rocks, on which was formed the terrace overhanging the banks of Loch Malcolm, had suddenly given way and opened without explosion, disclosing a profound abyss, into which the waters were now wildly plunging.

In another instant, among the shattered rocks and rushing waves appeared a canoe, which a vigorous arm propelled along the surface of the lake. In the canoe was seen the figure of an old man standing upright. He was clothed in a dark mantle, his hair was dishevelled, a long white beard fell over his breast, and in his hand he bore a lighted Davy safety lamp, the flame being protected by the metallic gauze of the apparatus.

In a loud voice this old man shouted, “The fire-damp is upon you! Woe—woe betide ye all!”

At the same moment the slight smell peculiar to carburetted hydrogen was perceptibly diffused through the atmosphere. And, in truth, the fall of the rock had made a passage of escape for an enormous quantity of explosive gas, accumulated in vast cavities, the openings to which had hitherto been blocked up.

Jets and streams of the fire-damp now rose upward in the vaulted dome; and well did that fierce old man know that the consequence of what he had done would be to render explosive the whole atmosphere of the mine.

James Starr and several others, having hastily quitted the chapel, and perceived the imminence of the danger, now rushed back, crying out in accents of the utmost alarm, “Fly from the mine! Fly instantly from the mine!”

“Now for the fire-damp! Here comes the fire-damp!” yelled the old man, urging his canoe further along the lake.

Harry with his bride, his father and his mother, left the chapel in haste and in terror.

“Fly! fly for your lives!” repeated James Starr. Alas! it was too late to fly! Old Silfax stood there, prepared to fulfill his last dreadful threat—prepared to stop the marriage of Nell and Harry by overwhelming the entire population of the place beneath the ruins of the coal mine.

As he stood ready to accomplish this act of vengeance, his enormous owl, whose white plumage was marked with black spots, was seen hovering directly above his head.

At that moment a man flung himself into the waters of the lake, and swam vigorously towards the canoe.

It was Jack Ryan, fully determined to reach the madman before he could do the dreadful deed of destruction.

Silfax saw him coming. Instantly he smashed the glass of his lamp, and, snatching out the burning wick, waved it in the air.

Silence like death fell upon the astounded multitude. James Starr, in the calmness of despair, marvelled that the inevitable explosion was even for a moment delayed.

Silfax, gazing upwards with wild and contracted features, appeared to become aware that the gas, lighter than the lower atmosphere, was accumulating far up under the dome; and at a sign from him the owl, seizing in its claw the lighted match, soared upwards to the vaulted roof, towards which the madman pointed with outstretched arm.

Another second and New Aberfoyle would be no more.

Suddenly Nell sprang from Harry’s arms, and, with a bright look of inspiration, she ran to the very brink of the waters of the lake. “Harfang! Harfang!” cried she in a clear voice; “here! come to me!”

The faithful bird, surprised, appeared to hesitate in its flight. Presently, recognizing Nell’s voice, it dropped the burning match into the water, and, describing a wide circle, flew downwards, alighting at the maiden’s feet.

Then a terrible cry echoed through the vaulted roofs. It was the last sound uttered by old Silfax.

Just as Jack Ryan laid his hand on the edge of the canoe, the old man, foiled in his purpose of revenge, cast himself headlong into the waters of the lake.

“Save him! oh, save him!” shrieked Nell in a voice of agony. Immediately Harry plunged into the water, and, swimming towards Jack Ryan, he dived repeatedly.

But his efforts were useless. The waters of Loch Malcolm yielded not their prey: they closed forever over Silfax.