"Here's your pocketbook, ma'am," said a nurse girl, picking it up.

"Thank you!" responded the old lady, relieved.

"What did I tell you?" exclaimed the dude triumphantly. "Boy, you're too fresh! I am a young man of high family. It is most ridiculous to charge me with stealing."

"I saw you with your hand in the lady's pocket," said Mark calmly.

"It's a lie! But I ought not to be surprised. I know you now. You were sent to the Island last summer for stealing. I remember seeing you on trial at Jefferson Market police court."

Suspicious glances were directed at Mark, for most people are inclined to believe evil of their neighbors--but the stout man only laughed.

"That is too thin, my friend!" he said. "Of course your motive in bringing a charge against this boy is plain.

"Let me out, sir!" stormed the crook.

"Madam, do you wish to bring a charge against this man?"

"No, let him go. I've got my pocketbook back, and that's all I want."

The stout man turned aside, and the adventurer sprang out of the stage and dashed down Thirty-Ninth Street in the direction of Third Avenue.

"I'm very much obliged to you, boy," said the old lady. "Did you really see that young man take my pocketbook?"

"I saw him with his hand in your pocket."

"I'm so sorry. He seemed so nicely dressed, too. I thought he belonged to a rich family."

The stout man laughed.

"My dear madam," he said, "the young men connected with our best families don't dress as flashily as your late companion. He is probably a professional pickpocket. Did you have much money with you?"

"Over a hundred dollars. I was going down town to pay a bill."

"Then you ought to be much obliged to this boy for detecting the thief."

"I am," said the old lady earnestly. "Here, take this," she continued, and she drew a five-dollar bill from her pocketbook.

Mark hung back.

"No, thank you!" he said. "I don't want any pay for that."

"Give me your name and address, then."

Mark had a business card in his pocket, and wrote his name and address upon it.

"Give me your name and address too," said the gentleman who had proved so valuable an ally. "I may need your services some time."

"I don't think I have another card, sir."

"Then take one of mine."

Mark glanced at the card offered him.

HENRY SWAN.

Watches, Diamonds, Jewelry.

No. 185 Broadway.

"Were that young man's diamonds bought at your store," asked Mark, smiling.

"They were only paste. They might deceive a novice, but I saw through them at once. But I must bid you good morning. I have to make a call at the Fifth Avenue Hotel."

A few blocks farther on the old lady got out.

Mark a.s.sisted her to the street.

"You're a very polite boy," she said. "You've done me a great favor. You had better take the five dollars I offered you."

"No, thank you, madam. I will wait till I have a chance to do you another service."

He did not resume his seat in the stage, having an errand on Eighteenth Street. As he was pa.s.sing Lord & Taylor's store, he heard his name called.

Turning in some surprise he saw Maud Gilbert, the young lady he had escorted to Daly's Theater, leaving the store.

"How do you do, Mark?" she said, extending her hand with a smile.

"Very well, thank you, Miss Gilbert."

"Didn't I see your picture in the _Evening Globe_ a short time since?"

"Yes, I believe so," answered Mark, blushing.

"In connection with Mr. Rockwell, the banker?"

"Yes."

"You have become quite a hero. I concluded it was you and I felt quite proud to think I knew you. Did I tell you that I had a brother about your age?"

"No, Miss Gilbert."

"I have, and he is home on a vacation from Exeter Academy. If you have no engagement on Thursday evening call and I will introduce you."

"I shall be delighted to do so Miss----"

"Maud," suggested the young lady smiling.

"Miss Maud. Thank you for the invitation. I will come."