"I shall have to stay here till I am let out," thought Mark.

He didn't worry particularly, as he knew that even if the rings were kept they would not involve his employer in any serious loss.

In about half an hour he heard steps ascending the stairs, then he heard a bolt shoved back, and he was not surprised when the young man, whose name he did not know, entered the room. He noted, not without amusement, that his face betrayed dissatisfaction.

"What does your aunt think of the rings?" asked Mark ingenuously.

"Look here, young fellow!" said Schuyler, sitting down and glaring at the messenger, "you've played a pretty trick on me!"

"What kind of a trick?" asked Mark, arching his eyebrows.

"These rings are not diamond rings."

"What are they, then?" asked Mark in assumed surprise.

"Paste—bogus!" answered Schuyler scornfully.

"Are you sure of that, Mr.——?"

"Schuyler."

"Mr. Schuyler."

"Yes. I took them round to a—jeweler, and had him test them."

"It must be a mistake," murmured Mark.

"It is a very strange mistake, then, for a first-class house to make," rejoined Schuyler in a tone of sarcasm.

"So it is. They must have given me the wrong rings," said Mark innocently.

"My aunt is very much disappointed. She wanted to start this evening for Buffalo."

"I thought she lived in Syracuse."

"She is going to visit her son in Buffalo," explained Schuyler with ready wit.

"I am really sorry. If she would go down to the jeweler's with me, or if you would, the matter could be set right at once."

Mr. Hamilton Schuyler thought over this suggestion, and on the whole regarded it favorably.

"I will go down in about an hour," he said. "You can explain matters to Mr. Swan. Just think if my aunt had taken the rings and paid full price for them, and not found out till she got to Buffalo that they were not genuine!"

"In that case Mr. Swan would have paid her the money or exchanged the rings."

"I hope so."

"Perhaps you had better hand me back the caskets, and I will carry them back to the store."

Mr. Schuyler returned the boxes to Mark, who opened them to see if the rings were inside.

"You will go down in an hour then?" he said.

"Yes, or—upon second thought you had better come right back with the genuine rings. I have an appointment at the Windsor Hotel, but will be back to receive them."

Mark understood why Schuyler did not care to go to the jeweler's. He could not get possession of the genuine rings without paying for them, whereas, if Mark should bring them, he could carry out his original plan and retain them by stratagem.

Schuyler accompanied Mark to the front door.

"Now hurry down and back," he said. "My aunt is anxious to catch the evening train."

"Very well, Mr. Schuyler."

At this moment Schuyler noted for the first time a familiar look in Mark's face.

"Haven't I seen you before?" he asked abruptly.

"Very likely," said Mark with self-possession. "Perhaps you have been in the store."

"No; my aunt called there, but I did not. You look very much like some boy I saw recently," and Schuyler wrinkled up his forehead in the vain endeavor to place Mark.

"I hope I remind you of a good-looking boy," he said, laughing.

"I see it now. You look like a telegraph boy I recently met in a Fifth Avenue stage."

"I should like to see him, but I shouldn't think you'd remember a common telegraph boy."

"He was impertinent to me, that is why I remember him," frowned Schuyler. "I hope to meet him alone some time. I will give him a lesson he won't be likely to forget."

"Then I'm glad I'm not the boy you mean. Good day!"

"Good day. Hurry back as fast as you can."

When Mark re-entered the jewelry store Mr. Swan advanced to meet him.

"Well," he said, "how did you make out?"

"I've got the rings with me."

"Did you see Mrs. Montgomery?"

"No, but I saw a young man who claimed to be her nephew."

"What did he say about the rings?"

"He left me alone in a back room on the second floor. When I went to the door I found that it was locked. But I didn't trouble myself. I concluded that he had gone out to pawn or sell the rings. He returned in half an hour quite angry, and told me he had ascertained that the diamonds were not genuine."

"Why did you think he went out to pawn or sell them?"

"Because I recognized him."

"You recognized him?"

"Yes, as the young man in the Fifth Avenue stage who robbed an old lady of her wallet."

"The day that we first met?"

"Yes, sir."

The jeweler looked surprised.

"Didn't he recognize you?"

"He asked if we hadn't met before. He said there was something familiar in my face. Finally, he said I reminded him of an impudent telegraph boy he had fallen in with. He wants to meet that telegraph boy alone," added Mark with a smile.

"He has had his wish."

"Yes, but luckily for me he didn't recognize me."

"How did you explain about the rings being false?"

"I said you had probably made a mistake."

"I see you are quick-witted. Well, was that satisfactory?"

"He expects me to bring back the genuine rings this afternoon, as his aunt wants to leave the city this evening."

"I think he will have to wait. Perhaps it may be as well to notify him that she needn't put off her journey on that account. I don't want to spare you to go there again, however."

"There's a boy I know out on the street," suggested Mark. "He would be glad to go."

"Who is it?"

"Tom Trotter, a friend of mine. He's a good boy, though he's only a bootblack."

"Is he reliable?"

"Yes, sir; I will answer for him."

"Very well. Call him in."

Mark went to the door and called "Tom! Tom Trotter!"

Tom looked around and recognized Mark.

"You ain't left de telegraph, have you, Mark?" he said.

"No, but I'm working here for a day or two. Would you like to go up town on an errand?"

"Yes," answered Tom with alacrity. "Will I be paid?"

"Of course. Can't you leave your blacking box somewhere and get your face and hands washed?"

"Yes, Mark; there's a small s'loon near by, where I hang out sometimes. Just wait for me and I'll be back in a jiffy."

Tom reappeared in a very short time with his appearance greatly improved by the application of cold water and soap.

"Mr. Swan," said Mark, smiling, "this is Mr. Thomas Trotter, the young gentleman I spoke to you about."

"Oh, stow that, Mark!" expostulated Tom; "I ain't Mr. Trotter. I'm Tom."

"Mr. Trotter," said the jeweler, smiling, for he had a sense of humor, "I have a letter here which I wish you to take to the address named."

"And to walk, sir."

"No; I will give you ten cents for car fare, and when you return and make your report you shall be paid for doing the errand."

"All right, governor."

Tom started up town, and in due time reached the house on Forty-Seventh Street.

He rang the bell, and the door was opened by the hall boy already referred to.

"Is Mr. Schuyler at home?" asked Tom. "I've got a letter for him."

Mr. Schuyler, who was anxiously awaiting Mark's return, came out of a room to the left of the hall. When he saw Tom he looked disappointed.

"I was expecting a boy from Mr. Swan's jewelry store."

"That's where I come from."

"Did you bring the rings?" asked Schuyler eagerly.

"I don't know nothin' about no rings," answered Tom. "I've brought you a letter."

"Give it to me quick."

He opened the letter, and this is what he read with contracted brow.

"Then it was the telegraph boy, after all!" ejaculated Schuyler in a rage. "I only wish I had known it. Are you a friend of—the telegraph boy?"

"Am I a friend of Mark Mason? I should smile."

"Step in a minute, then!" said Schuyler, with an assumed friendliness.

As the unsuspecting Tom stepped inside the hall, the young man began to shower blows on his shoulders with a cane that he snatched from the hat rack.

Tom was for a minute dazed. Then his wits returned to him. He lowered his head and butted Schuyler in the stomach with such force that the latter fell over backwards with an ejaculation of pain.

Then Tom darted through the open door, but paused on the steps to say, "With the compliments of Tom Trotter."

Schuyler picked himself up, uttering execrations, and looked for the boy, but he was gone!