"I think we've got it under control," said Bert, as he saw the flames beginning to die down. "If we don't have any more explosions, we'll be all right."

Fortunately there were no more, and, though the factory was badly damaged, the larger part of it was saved. But that was nothing compared to the satisfaction the members of the department felt over Bert's brave act.

In an hour more the last spark had been extinguished, and the chief gave orders for the engines to go back to quarters. It was the worst fire they had yet undertaken to fight, and the new engines had proved their efficiency in no uncertain manner. Little was talked of in town, the next day, but the fire and the sensational rescue.

As for Bert and his chums, they, too, had a fruitful subject for conversation. They had learned much from their experience at the box factory blaze, which was liable to stand them in good stead at future fires.

"I heard about you," remarked Mort Decker to Bert, when the next night he called at Cole's barn. "First thing you know you'll be getting offers from some big city department."

"Oh, I guess not. But how are things at the house of mystery? Have you discovered anything new?"

The two had walked out from the barn, to converse alone.

"I don't like the way things are going," replied the stenographer.

"Muchmore gave me several other deeds to copy to-day, and in some he had me change the descriptions and names. I don't like it. I'm sure, now, that he is a crook."

"Can you do anything?"

"That's just what I was thinking about. I have an idea he has some person a prisoner on that top floor, whom he is holding there until that person does as he wants, in the matter of some property."

"If we could only get word to Mr. Stockton," said Bert, "he might call in the authorities."

"Yes, if we could, that would be the very thing. But I don't know how to do it. I wrote him a letter, and mailed it in the post-office, but a little later I saw it on Muchmore's table. He must get Mr.

Stockton's mail, and forward it. And now I think Muchmore suspects me, because he probably opened that letter I wrote to his uncle. So we may as well take the bull by the horns, and do something."

"Yes; but what?"

Mort looked around to see that no one would overhear him.

"I'm going to make a try to get on that top floor," he said, "and I want you to help me."

"When are you going to do it?"

"To-night, in a little while. Muchmore is away, and there's n.o.body but the housekeeper there. We'll see who that mysterious prisoner is, who sends out typewritten messages asking for help. Will you come?"

"Sure. I don't have to stay here. It's my night off."

"Then come up to the Stockton mansion in about an hour. Go to the side door, knock three times, then a pause, then twice, and I'll know it's you, and let you in. We'll see if we can't solve the mystery."

About an hour after this conversation Bert knocked at the door of the big house as directed. The place seemed deserted, and there was not a ray of light to be seen.

"I wonder if he's here, or if Muchmore found out what he was up to, and drove him out," thought Bert, as he waited for an answer. But in a few minutes the stenographer admitted him.

"Don't make any noise," he cautioned. "Mrs. Blarc.u.m is in her room, but she has good hearing in spite of her age, and I think she is somehow mixed up with the mystery. Now we'll go to the top floor," and he took up a big poker, which was on a chair in the side hall.

"What's that for?" asked Bert.

"We may have to smash down a door or two, or pry them open. This is the only thing I could find. Now come on."

They cautiously ascended the stairs. When they reached the top floor, they found a stout door barring their progress. Mort Decker tried to insert the point of the poker in the lock, to force it, but, finding he could not do this, he raised the heavy iron, to break the panels.

At the first blow there sounded from the other side of the portal a cry:

"Help! Help! Let me out!"

"Who are you? Why arc you in there?" asked Mort, pausing in his attack on the door.

Before he could distinguish the answer, if one was made, there sounded from behind the two rescuers, a woman's scream, and they turned to see Mrs. Blarc.u.m rushing at them.

"Come away from there!" she cried. "Come away! Mr. Muchmore doesn't allow any one there!"

"I don't care what he allows!" retorted Mort. "We're going to get at the bottom of this mystery!"

Once more he rained a shower of blows on the door.

"Get away from there!" cried the old woman, rushing up, and grabbing the stenographer by the arm. "Help! Help!" she added. "Mr. Muchmore, he is breaking down the door to the secret corridor!"

Suddenly there sounded from below the rush of feet. Then came a startled cry.

"I'm coming!" some one shouted.

"Muchmore! It's Muchmore!" exclaimed Mort, pausing. "If he finds us here--"

"Let's stick it out!" urged Bert bravely. "We'll find out what this means!"

An instant later, Muchmore, his face distorted with anger, rushed upon them.

CHAPTER XXV

THE MYSTERY SOLVED--CONCLUSION

"Get away from that door!" yelled the enraged man. "What right have you to be prying into my affairs? I hired you to do copying work for me, not to roam about this house."

"Well, I'm done copying those illegal deeds for you!" retorted Mort.

"And, what's more, we're going to find out whom you have a prisoner in there!"

"A prisoner? You are joking. There is no one in there."

"Yes, there is. He wrote an appeal for help on the typewriter and tossed the paper from the window. Hark, you can hear him calling for help!"

There was a moment's silence, but no cry came from behind the door, one panel of which was shattered.

"You see," sneered Muchmore. "I guess you'll wish you hadn't begun this work, my friend, before I'm through with you. You'll be in jail ere you are many hours older. As for you," went on the man, turning to Bert, "I warned you, once before, not to trespa.s.s on my property. I shall also make a complaint against you. Now, clear out, both of you!"

"Suppose I refuse to go?" asked Mort coolly.