“Chasing him too close!” exclaimed Larry in bewilderment.  I only wish I was!  I haven’t the least clue to his whereabouts.  I wonder what he means?  Is that his writing?”

“I can’t be mistaken in that,” Grace replied.  “It is just the same as the other letter was.”

“Let me see,” and the young reporter examined the envelope.  It was similar to that containing the first note which had come from Mr. Potter, save there was no blot on it and the stamp showed no excess of mucilage.

“I’ll take this to the sub-station,” Larry went on.  “It was probably mailed in the same place as was the other.  I’ll see if the carrier had any such experience as he did with the former note.”

“I think it would be a good plan,” Grace answered.  “Oh, this is beginning to wear on my nerves!  As for mother, she is almost ill over it.  Her physician says if father is not found soon he cannot say what will happen to mother.”

“Still she must know your father is safe.”

“That is the worst of it.  She will not believe these notes are from him, or, rather, she believes he is held captive somewhere and is forced to write them.  Nothing I can say will make her think differently.  She is wearing herself to a shadow over it.”

“We must do something!” exclaimed Larry.

“Yes; but what?” asked the girl.  “You are working hard and I am doing all I can, but our efforts seem to amount to nothing.  What more can we do?”

“I’m trying to think of a plan,” Larry responded.  “The search of the steamship piers gave us no clue; the police here have not been able to find a trace.  We can try one thing more.”

“What is that?”

“You can hire private detectives.  Sometimes, in cases of this kind, they are better than the police, as they assign one man, who devotes all his attention to the search, while the police, as a rule, don’t bother much to find missing persons.”

“Then I’ll hire the best private detectives to be had!” exclaimed Grace.  “Where ought I to go?”

Larry named an agency, that he had heard was first-class, and offered to take Grace to the office.  The reporter knew one of the men on the staff, as he had once written a story in which he figured, and the officer had been grateful for the mention of his name.  Detectives, even private ones, are prone to vanity in this respect, as a rule.

“I don’t like to take up so much of your time,” objected the girl, as Larry prepared to go with her to the detective agency.

“My time is yours in this case.  I have nothing to do for the Leader but to find your father.  This is part of the work.”

“I wouldn’t think it could pay a newspaper to put one man exclusively on a case like this.”

“The editors think it does.  In the first place it makes some news every day, and the papers have to have news.  Then if I should happen to find Mr. Potter, it would be a big advertisement for the Leader, and that is what all the New York papers are looking for.  The better advertised they are the better prices they can charge for the advertisements printed in them, for it’s from the advertisements that a newspaper makes its money.  Besides, I’ve promised to find your father for you and I’m going to do it!” Larry looked very determined.