Mr. Jones was expecting Derrick that evening, and was waiting somewhat impatiently for him. When the boy at last arrived he was taken into the library, where, as soon as the door was closed, the mine boss asked:

“Well, Derrick, have you heard anything more about the meeting?”

“Not a word, sir.”

“To-morrow is the 27th, you know.”

“Yes, sir, I know it is.”

“And my fate, and perhaps yours too, may be decided within twenty-four hours from now.”

At this Derrick started; he had not realized that he was in any particular danger.

“Do you think, sir, they would pay any attention to a boy like me?” he asked.

“I certainly do,” replied the mine boss. “They would pay attention to anybody or anything that stood in their way, or seemed likely to interfere with their plans. I am afraid, from what Job Taskar said the other day, that they consider your presence in the mine as dangerous to them. I am sorry that my liking for you, and efforts to promote your interests, should have placed you in such an unpleasant position. If you like I will try and get you a place as errand boy in the main office of the company, where you will be in no danger.”

“Oh, no, sir!” exclaimed Derrick. “Please don’t think of such a thing. I’d rather take my chances with the Mollies in the mine than go into an office. There I should never be anything but a clerk; while here I may some day become an engineer, as my father was. Don’t you think I may, sir?”

“Yes,” answered the other, smiling at the boy’s earnestness, “I think any boy of ordinary intelligence and blessed with good health can in time occupy any position he chooses, if he directs his whole energy in that direction, and makes up his mind that no obstacle shall turn him from it.”

“I have made a beginning, sir,” said Derrick, much encouraged by these words from one who was so greatly his superior in age, knowledge, and position, and whose opinion he valued so highly.

“Have you?” asked the mine boss, with a kindly interest. “In what way?”

“I am studying my father’s books, and trying to work out problems from some old plans I found among his papers. One of them is a plan of the very oldest workings of this mine, and I have brought a tracing of a part of it to show you.”

“Very good,” said Mr. Jones, glancing at the tracing carelessly. “I have no doubt that in time you will become a famous engineer.”

Although this was spoken kindly enough, it was evident that the speaker’s thoughts were far away, probably trying to devise some means for being present at the approaching meeting in the mine.

Noting this, Derrick said, “I did not bring the tracing just to show what sort of work I could do, sir, but because I think it will lead us to where we can hear what they say at that meeting.”

Instantly the mine boss exhibited a new interest. “Explain it,” he said.

Then Derrick told him of the old drift-mouth he had discovered, and said he felt confident that if they followed the gangway leading in from it they would reach the top of the old air-shaft into which Bill Tooley had fallen, and up which had come the voices of the Mollies at their previous meeting.

“If we could get there by this back way it would be capital!” exclaimed the mine boss. “In that case my presence in the mine would be unknown and unsuspected; whereas, if we should go in as you did, from the other end of the old gangway, we could hardly escape discovery. If that route proves practicable a great load is lifted from my mind; for, somehow or other, I must find out what these Mollies are up to. You are of course sure of the correctness of the plans?”

“My father drew them,” answered Derrick.

“I was not questioning your father’s accuracy; I only wanted to know if this tracing was an exact copy of the original.”

“Yes, sir, it is,” answered Derrick, though with a slight hesitation in his voice as he thought of the one place he had not been quite sure of. This was where the plan had been somewhat blotted and blurred, so that he could not see whether or not two lines joined each other. Having made up his mind that they ought to be joined, he had thus drawn them on his tracing. It was such a small thing that he did not consider it worth mentioning. Thus, without meaning to make a false statement, he said that his tracing was an exact copy of the original, and by so doing prepared the way for the serious consequence that followed.

Derrick was a fine, manly fellow, and was possessed of noble traits of character, but like many another boy he was inclined to be conceited, and to imagine that he knew as much if not a little more than his elders. Nor was he backward in parading his knowledge, or even of allowing it to appear greater than it really was.

In the present instance he was proud of the confidence reposed in him by the mine boss, and of the skill with which he had prepared the plan of operations they were now discussing. It really seemed to him that he was about to become the leader in a very difficult enterprise in which the other was to be a follower.

The mine boss, with a quick penetration of human character, gained by years of study and experience, suspected something of this weakness on Derrick’s part, but did not consider that either the proper time or opportunity had yet come for warning him against it.

So Derrick’s plan was discussed in all its details, and before they separated that night it was adopted.

In order that the mistake made by Derrick in his slight alteration of the plan of the old workings, as shown in his tracing, may be understood, a few words of explanation are necessary.

The old drift-mouth, that he had discovered almost hidden beneath a tangle of vines and bushes, was on a mountain side above a deep valley. Farther down was the mouth of a second drift, which he had not discovered, and knew nothing of. On the opposite side of the mountain was another valley, the bottom of which was on about the same level as the higher of these drifts. The old workings ran from them through the mountain, and under this valley in which the present colliery was located.

When the gangway from the upper of the two drifts had been opened as far as the valley, the vein that it followed took a sudden dip. The gangway was in consequence changed into a slope, which finally led into the workings beneath. Some time after they had been abandoned a great “break” or cave-in of the ground above there had occurred at the edge of the valley, and by it an opening was made into the lower set of workings. It was on the opposite side of the valley from this break that the new workings were now being pushed; and somewhere between it and them was the old air-shaft and the chamber that the Mollies had selected as their place of secret meeting.

Now Derrick had got hold of a plan of the lower set of these old workings which he knew nothing of, and thought it was a plan of the upper set, which in reality only extended to the edge of the valley. He knew that the upper drift-mouth was on about the same level as the top of the old air-shaft, and thought he had a plan showing that the two were connected. He reasoned that by entering the old gangway at the break, and following it under the valley, they would not only save distance, but would be conducted directly to the top of the air-shaft which they wished to reach. By the joining of those two lines at the blurred place on the plan it was made to conform so perfectly to this theory that he felt satisfied his conclusions were correct, and consequently made his confident statements to Mr. Jones.

The latter had been connected with the Raven Brook Colliery but a few months, and knew nothing of its old and abandoned workings, not yet having found time to study their plans or explore them. He did know, however, that Mr. Sterling had been one of the company’s most trusted engineers, and that Derrick had long been interested in poring over and tracing his father’s plans of these very workings. When, therefore, he had carefully examined the tracing that the boy had made, and now assured him was an exact copy of the original plan, and found that it showed a system of galleries by which the top of the air-shaft might be gained from the break, he had no hesitation in saying that they would make the attempt to reach it from that direction. Had he sent for the original plan he would have quickly discovered Derrick’s error. He thought of doing this, but did not, for fear of wounding the lad’s feelings by appearing to mistrust him.

It was arranged between them that Mr. Jones should leave the village on the afternoon of the 27th, as though bound on some distant expedition, and have it understood that he might possibly be absent all night. An hour before sundown he was to be at the break, prepared to explore the old gangway to which it gave entrance. Here Derrick was to meet him, after having left the mine an hour earlier than usual, gone home for supper, and told his mother that he should be out late on some business for the mine boss.

This plan was successfully followed, without suspicion being aroused, and the young mine boss met his boy companion at the appointed time and place. They both had safety-lamps, and each carried a small can of oil, for they did not know how long they might have to remain in the mine.

In the break they found a rickety ladder that had been placed there for the use of the village children, who were accustomed to come here with baskets, and in a small way mine coal for home use from the sides of the old gangway. Descending this, they lighted their lamps at the bottom, and entering the black opening began to follow the path marked out on Derrick’s tracing.

For some distance the way was comparatively smooth, and they made rapid progress. Then they began to encounter various obstacles. Here a mass of rock had fallen from the roof, and they must clamber over it. In another place a quantity of waste material had so dammed a ditch that for nearly a quarter of a mile the gangway was flooded with cold, black water, through which they had to wade. It was above their knees, and, filling their rubber boots, made them so heavy as to greatly impede their progress. In several places where the old timber props had rotted out, such masses of rubbish choked the gangway that they were compelled to crawl on their hands and knees for long distances through the low spaces that were still left. Once they were on the point of turning back, but animated by the importance of their errand they kept on, cheering each other with the thought that they would not be obliged to come back this same way in order to leave the mine.

During the earlier portion of the journey, as they encountered these obstacles, the mine boss urged, almost commanded, Derrick to go back and leave him to continue the undertaking alone. In spite of some faults the lad was no coward, and he begged so earnestly to be allowed to keep on that the other consented, on condition that no greater danger presented itself.

At length they had overcome so many difficulties that the road behind them fairly bristled with dangers, and the young man felt it would be an act of cruelty to send the boy back to encounter them alone.

Now and then, as they crawled over piles of fallen debris, and there was but little space between them and the roof, the flames within their safety-lamps burned faint and blue, and they breathed with great difficulty. The mine boss knew they were passing through spaces filled with the deadly “fire-damp,” and he urged Derrick to make all possible haste towards more open places where they could keep below its influence.

They passed through a door in a fair state of preservation, but fairly covered with the pure white fungus growth of glistening frost-like sprays, which in the mine are called “water crystals.” Everywhere were the signs of long neglect and decay, and unenlivened by the cheering sounds of human toil the place was weird and awful. The very drippings from the roof fell with an uncanny splash that struck a chill into Derrick’s heart. Long before they reached the end of their journey he regretted having planned and proposed it; but he bravely kept his fears and regrets to himself, and plodded sturdily on behind his companion. As for the latter, his thoughts were also of a most dismal character. He realized even more fully than Derrick the dangerous position in which they had placed themselves, and felt that his experience should have warned him against such an undertaking.

Meantime those who were to meet in the old chamber at the bottom of the air-shaft were already gathered together, and were earnestly discussing the affairs of their order. Job Taskar, as presiding officer, made a long speech. In it he denounced the mine boss for discharging several of their members, and refusing to take them back, though petitioned to do so by a large number of those who remained at work. He also charged him with placing a spy in the mine in the person of Derrick Sterling, and of having removed the son of one of their most prominent members to make room for him. At this point he looked steadily at Monk Tooley.

“Don’t yer say nothin’ agin Derrick Sterling,” growled that miner, “fer I won’t hear ter it. He’s doin’ fer my lad this minute what dere isn’t anoder man in de meetin’ er in Raven Brook Colliery, nor I don’t believe in de State, would ha’ done in his place.”

“Do yer know what he’s doing it for?” interrupted another member, springing to his feet. “No, yer don’t, an’ yer can’t make a guess at it; but I can tell yer. It’s for revenge, an’ nothing else. I heerd him say it his own self to Paul the cripple, coming down the slope, only yesterday morning. ‘I’m taking out my revenge on him,’ says he; them’s his very words.”

“All right,” replied Monk Tooley, “if yer heerd him say it, den he’s doin’ it fer revenge, and it’s de biggest kind of revenge I ever knowed of a man or a boy ter take out on anoder. Do yer know dat he’s give up his own bed ter my Bill, an’ dat he sets up nights awaitin’ on him an’ a-nussin’ of him? No, yer don’t know nothin’ about it, an’ I don’t want ter hear anoder word from yer agin him. I’m his friend, I am.”

An awkward silence followed this announcement, for the members thought that perhaps if Monk Tooley were Derrick Sterling’s friend, he might also be a friend of the mine boss, whom they had almost decided should be put out of the way.

The silence was finally broken by Job Taskar, who asked sarcastically if Monk Tooley knew who stole his three checks from the check-board two days before.

“Yes, I do,” answered the miner, promptly.

“Then you know it was this same sneaking boss’s pet, Derrick Sterling.”

“No, I don’t.”

“I tell you I saw him do it!” cried Job, in a rage. “Him and the hunchback went up to the board together, and when the boss stepped away, so they thought nobody wasn’t looking, the pet slipped ’em into his pocket. I saw it with my own eyes.”

“An’ I tell yer yer lie!” shouted Monk Tooley. “Here’s de checks, an’ dey come outen yer own pocket, yer black-hearted old scoundrel!”

At these astounding words Job Taskar sprang towards Monk Tooley with clinched fists, as though to strike him, and all present watched for the encounter in breathless suspense.

Just then the door behind them was pushed open, and standing on its threshold they saw the mine boss and Derrick Sterling.