“Mah good land of massy!” ejaculated the negro.  “It’s de train newsboy whut yo’ give a dollar to las’ night, Colonel!”

“The one who wanted to sell me a detective story?”

“I’m him, Colonel Brentnall,” answered the lad, a smile of triumph lighting up his face.  “Your man told me who you was, and I heard you tell the taxi man where to drive you.  I didn’t think anything more about it until I read about the murder.”

“The murder!” exclaimed the colonel.  Somehow that seemed to follow him as a Nemesis.

“Yes—­old Mrs. Darcy—­the jewelry store lady,” went on the boy.  “This young lady,” and he nodded toward his companion, “when I told her—­”

“Perhaps you had better let me explain, Tom,” broke in the girl.  “You see it’s this way,” she went on, addressing the colonel.  “This boy is Tom Tracy.  He sells papers on the express.  He was once a jockey for my father, but he got hurt—­stiff arm—­and we had to get him something else to do.  Dad always looks out for his boys, and so Tom went on the road.”

“I had to do something that had motion in it,” Tom explained in an aside.

“Yes, it was as near to horseback riding as he could come,” said the girl, and she smiled, though the grief did not leave her blue eyes.  “Well, as he has told you, he heard who you were, Colonel, from your man.  Then when he read about the murder, and found how—­how close home it came to me, he hurried out to our place and said I should engage you to help—­”

“He’s the biggest detective in New York!” broke in Tom.  “And that’s what we need—­a big New York detective!”

“But what’s it all about?” asked the colonel.  “This is talking in riddles, though I begin to see a little—­”

“I beg your pardon,” said the girl.  “I should have told you who I am.  My name is Amy Mason, and—­”

“Ah!  You are engaged to be married to James Darcy, who is—­er—­detained as a—­er—­as a witness in the murder of his cousin?”

“I am,” and she seemed to glory in it.  “As soon as I heard what had happened—­to him—­I wanted to help.  They would not let me see Jimmie at police headquarters, but I sent word that dad and I were going to work for him every minute.”

“That must have cheered him.”

“I hope it did.  But I want to do more than that.  I want to help him!  I want to get the best detective in the country to work on the case and prove that Jimmie didn’t do this—­this terrible thing of which he is accused.”

“He isn’t exactly accused yet, as I understand it, Miss Mason.”

“Oh, well, it’s just as bad.  He is suspected.  Why, Jimmie wouldn’t have caused Mrs. Darcy a moment of pain, to say nothing of striking her—­killing her!  Oh, it’s horrible—­horrible!” and she covered her face with her hands.

“I don’t quite understand,” began the colonel, “why you came to me, or how—­”