"Do it again, Betty. He might be asleep or something," suggested Mollie, with a glance over her shoulder at the quiet woodland. "Knock harder this time."

Betty obeyed, but with no better success than the first time. Everything was as silent as before.

"Isn't there a bell, I wonder?" suggested Amy, wishing ardently that they were back on the road once more. "Perhaps your knock isn't loud enough for him to hear."

"We might tap on the window," suggested Grace. "If I use my ring on the window pane he surely ought to hear that."

She started to suit her action to the words when an exclamation from Betty made her pause. The latter had tried the door and found to her surprise that it gave to her touch.

"The door is unlocked," she said. "I don't believe the professor is in here at all and if he has gone into the woods to hunt his butterflies and beetles I am sure he wouldn't mind our going inside. What do you think?"

She was about to push the door open, but Grace detained her with a nervous hand on her arm.

"Oh, I don't think we had better go in, Betty!" she cried. "You know what we were speaking of in the car. Suppose we should find that he has-- that he has----"

"That he has what?" asked Amy, her eyes wide. "For goodness' sake, what do you mean, Grace?"

Betty tried to stop her, but Grace hurried on heedlessly.

"He may have committed suicide," she cried, adding, in response to Mollie's and Amy's cry of horror: "You know he must have been desperate enough to do anything, poor old man, out here all alone."

At the conviction in Grace's tone, Betty felt her own nerve slipping. She did not want to go into that silent house any more than the other girls did. Every instinct in her commanded that she run from the place to the commonplace safety of the road. She was afraid of what she might find on the other side of that unlocked door. And yet----

"I'm going in," she cried, and, suiting the action to the word, pushed the door quickly open and stepped over the threshold.

Emboldened by her example, the other girls followed and stopped short with a cry of dismay. They had not found what they feared-- but something almost as bad.

The room, which had been so neat and orderly when they had last seen it, was now the scene of such utter confusion as one might only hope to see depicted in a cubist's nightmare.

The animal skins which had adorned the walls had been torn down and lay in a tattered heap upon the floor. The shelves upon which had rested the professor's botanical specimens had been swept clean and their contents also were scattered about the floor.

The bench upon which the girls had sat and partaken of the queer little man's hospitality was overturned and the one chair in the room was upside down on top of it. The whole room looked as though a cyclone-- or a maniac-- had been at work.

The girls stared for a minute and then drew closer together as if seeking protection from some unseen menace. They had some vague conception of what had taken place here in this lonely little cottage. The elderly and already nervous professor, reading the tragedy of his sons' death, all alone perhaps, with no one to comfort or restrain him, had lost his mind, temporarily at least, and had found an outlet in ruthlessly destroying everything which came within reach of his hand.

And if this were so, might he not even now be hiding about somewhere, watching them, perhaps?

This thought seemed to strike the girls at the same time, for after peering for a second about the room, they turned and made a concerted dash for the door.

Once outside the room, in the reassuring sunshine, they turned and looked at each other sheepishly. Then Betty wheeled about and started for the door again.

"Betty, you are never going back into that place again?" cried Amy wildly, holding to her skirt. "I won't let you! Do you hear me? Come back here!"

But Betty had no intention of coming back. She turned and faced the girls calmly, though inwardly she was trembling.

"Of course I am going back," she said. "Professor Dempsey may be in one of the other rooms and he may be sick. If nobody will go with me, I'm going in alone."

Of course the three girls could not let her go in alone, so they trailed back at her heels into the house, being very careful, however, to leave the door wide open behind them, in case a hasty retreat became necessary.

Cautiously Betty opened the door at the other end of the room and stepped into what had evidently been a sort of rough kitchen. Now it was nothing but a nightmare like the other room, and she shuddered as she looked about at the desolate confusion.

There was a door at the farther end of this room, and after some hesitation and an inward struggle Betty crossed hastily to it and flung it wide open.

What she half expected and feared to find there nobody but Betty herself ever knew, but whatever it was, she gave a great sigh of relief at not finding it there. The room was upset, though not quite as badly as the other two, but there was no sign of human occupancy anywhere.

She turned to the girls who had come up behind her and were eagerly and half shudderingly peering over her shoulder.

"There's nothing here," she announced, the relief she felt showing in her voice, "and as there doesn't seem to be any other room in the place, I suppose we might as well go back."

Echoing her suggestion heartily, the girls started to retrace their steps when a slight sound in the other room made them stop short in a panic.

"What was that?" Amy questioned, but Mollie held up her hand impatiently.

There came the sound of some one stumbling over something. This was followed by a muttered exclamation.

While the girls looked about them wildly for a means of escape Mollie began to laugh hysterically.

"We have a visitor," she announced in a strangled voice. "And he is between us and the only door in the place. Come on, girls, let's see who it is."

They stepped out into the cluttered living room and came face to face with a young man who seemed more startled at seeing them than they had been at sight of him.

"Well, I'll be jiggered!" he exclaimed, and at sound of the commonplace phrase the girls could have hugged the speaker in relief. Also they felt a rather hysterical desire to laugh long and foolishly.

As it was, the stranger stood staring at the girls and the girls at him so long that the funny side of the situation struck Betty and she really did begin to laugh.

"We haven't the slightest idea who you are," she told the astonished young man. "But I am sure of one thing, and that is that we were never so glad to see any one in all our lives as we are to see you."

CHAPTER X

HURRAH FOR ALLEN

The young man stared for a moment longer. Then the humor of the situation seemed to strike him too, and he smiled pleasantly.

"It surely is a pleasure to be as welcome as all that," he said pleasantly, and the girls noticed that he was a well set up young fellow and that he wore his uniform easily, as if he had been used to wearing it for a long, long time. "I am Wesley Travers," he went on. "I live in a cottage down the road and I came over this way to see if the old professor had come back yet. I saw the door open-- came in-- and found you."

He smiled again pleasantly and looked as though he considered that he had fallen into rather good luck. But at his mention of the professor Betty had sobered instantly.

"Oh, then you know something about Professor Dempsey?" she questioned eagerly.

"Please tell us what happened to him," added Amy breathlessly.

"Did he do this?" asked Mollie, with a comprehensive sweep of her hand about the cluttered room.

"I'm afraid he did," answered the young fellow, sobering instantly. "You see, I just returned from overseas about a week ago and a couple of days later my dad read in the paper about the death of this queer old man's two sons. The pater had always been interested in the lonely old boy, so he sent me over to see if I could do anything for him. I found the place like this and-- the bird had flown. Went dopy I suppose about the bad news and tore things up a bit."

Though the boy's words were slangy, there was real sympathy in his tone and the girls liked him the better for it.

"And you haven't heard anything from him since?" asked Betty softly.

"Not a word or a sign," answered the boy, with a shake of his head. "Just clean cleared out, that's all. Pretty hard luck, I call it. Just at the end of things too-- when he had a right to expect the fellows