Never since she had been Principal of West Haven High School had Miss Gray been so upset as she was now. For the first time a scandal was connected with her beloved institution. Every day there was a new complaint.

“Miss Gray, I only left my ring on the washstand a minute, while I was washing my hands, and when I looked for it, it was gone,” said one girl.

“But who was in the washroom, Julia?” asked the Principal wearily. She was disgusted and angry with this troublesome situation.

“Oh, all the girls, Miss Gray, but nobody saw any one take it.”

Small purses containing lunch money were emptied of their contents and put back into jacket pockets. Some of the teachers lost money and Miss Gray herself was robbed of ten dollars, the wages of the old janitor, which she had placed under a paper weight on the desk, in her own private office.

The whole school had gone distracted, but the pilferer was too clever to be caught.

Twice Miss Gray had summoned Mary Price to her office, but, after looking gravely into the young girl’s serious eyes, she kissed her and sent her off on some improvised errand.

“I shall wait a few days,” the Principal said. “After all, there may be some mistake.”

And it was then that she determined to try an experiment.

One bleak autumn afternoon a thick, wet mist rolled in from the ocean and enveloped the town of West Haven so densely that it seemed like a city floating on a bank of cloud. Only the dim outline of objects twenty yards away could be seen and the muffled call of the fog horn at the lighthouse on the Black Reefs sounded its dismal warning through the mist.

Billie and Mary were hurrying arm in arm down the street in earnest conversation. Notwithstanding it was after school hours, they were going toward the High School.

“Do you think we can get it, Mary?” Billie was saying.

“Oh, yes, the janitor always leaves the door to the basement corridor open until evening for Miss Gray and the teachers who sometimes stay late.”

“It was stupid of me to have left that horrid old algebra, but you know I always forget the things I don’t like. If Miss Finch hadn’t called me down so thoroughly this morning about my average in mathematics, I would just let the lesson for to-morrow go, or if Miss Finch were only Miss Allbright, or Miss anybody else but just a stern, animated mathematical cube.”

“She’s all right if you know your lessons,” said Mary, smiling. “It’s only the ones who don’t study hard enough to suit her who call her a human arithmetic.”

The door to the corridor was open, as Mary had predicted, and the girls entered, their footsteps resounding with a hollow echo through the empty place.

“‘I feel like one who treads alone some banquet hall deserted,’” quoted Billie. “Could anything be more ghostly than a deserted school?”

“It’s not deserted,” said Nancy. “I heard voices somewhere, I am certain of it, just as you opened the door.”

They paused and listened for a moment, but the place was as still as a tomb. A dim gas-light burned in the long corridor, on each side of which were the arched entrances to the locker rooms of the various classes, wash rooms and Miss Gray’s own private office.

“It reminds me of the catacombs in this light,” whispered Billie. “I’m almost afraid of the sound of my own voice.”

The girls slipped silently down the passage to the stairway leading to the class rooms. At her desk in the sophomore study room on the third floor Billie found her algebra. As she gathered together some of her scattered papers in the not over tidy interior of the little one-seated desk form, and searched for a certain favorite stubby pencil which she claimed brought her good luck with her problems, Mary at her own desk gave a cry of dismay and sat down limply.

“What was it, a mouse?” asked Billie, her voice sounding quite loud in the empty room.

“Oh, Billie, Billie, no, it was not a mouse. It was fifty dollars,” cried Mary. “I found it just now in my desk.”

“Fifty dollars?” echoed Billie, slipping her algebra into her pocket and hurrying over to her friend’s desk. “Are you playing a trick on me, Mary?”

“Listen, Billie,” said Mary. “I’m going to tell you something. I believe I am the victim of some kind of conspiracy. You know of course about all of the things that have been stolen from school lately?”

“Yes, but I haven’t had any losses myself; so I haven’t talked about it much to the others.”

“Of course you had no idea that I was supposed to be the thief,” Mary went on, with a sort of dry sob in her voice that was more heart-breaking to Billie than real weeping would have been.

Mary told her the story of Fannie Alta and the twenty dollars.

“I didn’t tell it before,” she continued, “because I was so ashamed somehow, I couldn’t bear for any one to know it.”

Billie’s heart swelled with indignation.

“The little wretch,” she exclaimed, “you should have gone straight to Miss Gray about it, Mary.”

“I know it, and I am sorry now I didn’t, but I thought she wouldn’t dare do it again, and she hasn’t, but things are disappearing all the time, and I believe she has told it around school that I took the twenty dollars and all the other things. Nobody has said anything, of course, but I can’t help feeling that they are all whispering about me whenever my back is turned.”

“You poor, blessed child,” exclaimed her friend. “And all this time you have been keeping it secret and suffering in silence.”

Mary nodded her head.

“And the worst of it is, Miss Gray suspects me too. But she is not going to say anything until she is sure. I thought of talking to her about it, but it would look as if I had a guilty conscience to complain before I am accused.”

“How dare any one suspect you of stealing,” cried Billie, putting her arms around her friend and kissing her warmly. “Would Miss Gray or any one else be so stupid as to take the word of Fannie Alta before yours?”

“But nobody has said anything that I know of,” groaned poor Mary. “It’s all in the air. That is why I don’t know what to do. Suppose after all I was mistaken and they didn’t suspect me. Suppose I took this money to Miss Gray and suppose she would think that I had taken all the other things and was just returning this because I had lost my nerve and suppose—suppose——”

“But, Mary,” remonstrated Billie, “why suppose anything at all so awful? Why not suppose that Miss Gray will listen to you and believe every word you say. You are perfectly innocent and nothing on earth can make you guilty. Of course Fannie Alta must have left the money in your desk, though where she got so much is a mystery to me.”

“But I tell you I am frightened, Billie. Such wretched things do happen and innocent people often suffer for guilty ones.”

“Nonsense, Mary, you must not lose your nerve in this way. Take the money and go straight to Miss Gray with it now. I will go with you.”

The two girls gathered their things together silently. Mary put the roll of money in her jacket pocket and they made for the door. It was almost dark now and the rows of empty desks down the big room were like kneeling phantoms in the half light.

“Did you hear anything?” whispered Mary as they reached the door.

“I heard a step,” answered Billie in a low voice. “It was probably the janitor.”

With a mutual impulse they clasped hands and a wave of fear swept over them when they found that the door would not open.

“It must have stuck,” whispered Mary. “Try it again.”

But the door was locked fast.

“There is only one way for you to get back the key to the door, young ladies,” said a voice so near to them that they both jumped back as if they had been struck in the face.

The person who had spoken had been standing flat against the wall at the side of the door. He emerged from the shadows, as quietly as a shadow itself, and in the twilight his long, lank figure seemed almost to be floating in space. The small black mask which covered his face and his whole appearance reminded Billie of a gruesome picture she had once seen called “The Black Masque.”

“You have a small sum of money there,” he went on, “which you evidently do not wish to keep and which I would be pleased to have and can use at once. By a strange coincidence, I happened to overhear your conversation, you see, and as the money appears to belong to nobody and is exactly the sum I require I must have it.”

Mary tried to speak, but her lips refused to form the words, and she had no voice left. There was a sound in Billie’s ears like the pounding of surf on the beach and she felt quite dizzy.

“This is fright,” she found herself saying, as a wave of homesickness for her father swept over her.

“Oh, papa, papa,” she whispered.

The man had seized Mary’s two hands in one of his with a grip of steel, while with the other he felt in her jacket pocket, took the roll of money, pushed Billie roughly from the door, and with a laugh pulled back the bolt; there had been no key after all. The next instant he had slipped downstairs as softly as a cat and was gone.

The girls followed after him like two sleep walkers.

“We’ve been robbed, Billie,” moaned Mary, giving her dry sob. “The fifty dollars is gone. What shall we do now?”

Billie did not reply. She wanted to get out of that dark stuffy school building, and breathe in some fresh air before she dared trust her voice. It was good to feel the wet fog again in their faces as they hurried up the street.

“Why not still tell Miss Gray, Mary?” asked Billie at last, but already there was a feeling of doubt in her heart. It was certainly a very unlikely sounding story, a robber in the school room.

Suddenly a figure loomed up in the mist. It was Miss Gray herself.

“You are out late, girls,” she said as she hurried past, and for some reason they both had an uncomfortable feeling of having done something wrong.

Miss Gray hastened into the school building just as the janitor appeared to lock up.

“Jennings,” she said, “switch on the light in the sophomore study room. I shall only be there a moment.”

The janitor shuffled after her and turned on the light while Miss Gray opened Mary’s desk. She sighed deeply and shook her head.

“She must have got here before me,” she thought. “It was cruel to tempt the child at such a time as this when her mother is in great need of money. I felt so sure she would bring it straight to me and that was the only test I required. Oh, dear, what a crooked world this is. I am out fifty dollars. But how will the poor child ever explain all this money to her mother? She must have saved a good deal out of her pilfering——”

Miss Gray’s disconnected train of thought did not bring her any comfort, as she slowly descended the three flights of steps into the basement and plunged into the mist again.

“At least I shall wait a day or two,” she continued. “The child may think better of it. She might have stopped me this evening, though. At all events I deserve to lose the money. It was a silly, stupid impulse, but I was so sure—so very sure——”

The mist had grown so thick now that the Principal walked very slowly, keeping close to the fence in order to guide herself to the corner where she must turn to go to her own home. A voice reached her through the fog. Someone was coming up from behind.

“I have procured fifty, SeÑor, a curious lucky stroke, and from a schoolroom, too—would you have believed——” the voice broke off in a laugh.

“Be careful——” said another voice, and two figures passed Miss Gray in the fog and were swallowed up again immediately.

“Is it possible,” she exclaimed, “robbers in West Haven High School? What does it mean? And I have been blaming that innocent child. What an imbecile I have been!”

Her last resolution before sleep came to her that night was to notify the town police in the morning and hire a detective to stay about the High School day and night.

Imagine the surprise of the bewildered Principal, when, next morning bright and early, Mary Price, after a timid knock on the office door, came hesitatingly into the room.

“Miss Gray,” she said, “I found this money yesterday afternoon in my desk. I don’t know how it came there nor whose it is. But it would be better for you to take charge of it until the owner asks for it.”

Mary spoke quickly, as if she had learned the little speech carefully by heart. There was a strange expression on Miss Gray’s face as she took ten crisp new five-dollar bills from the young girl’s outstretched hand.

“This is not even the same money,” she thought, forgetting to answer Mary in her amazement. “Am I losing my senses or is the child a deep dyed villain?”

Mary flushed scarlet under the Principal’s steady gaze, but she did not lower her eyes, and there was not a sign of guilt in the expression of the sad little face.

“Very well, dear,” Miss Gray said at last.

Mary, as she closed the door behind her, was more mystified than Miss Gray.

“I should think she would have shown a little surprise,” she said.