“Of course,” Grace replied, in a way that showed she was used to having her own way.  “When will you come for me to-morrow?”

“In the morning.”

“I can hardly wait.  Now don’t forget.  I’ll be your assistant.  Maybe I could learn enough to be a woman reporter some day.”

“I have no doubt you could,” Larry responded, as he went out on his way to the sub-station with the envelope, having telephoned to the police of the letter and securing a promise that no other reporters would be informed of it for a while.

As he walked along, his thoughts were busy in many directions.  The receipt of the letter, the clues the envelope offered, the plans for a search among the ship captains, and, above all, Grace’s offer to accompany him, made Larry speculate on what the Potter mystery was coming to.

“I wonder what the other fellows on the Leader would say if they knew I was working this assignment in company with the millionaire’s daughter,” said Larry to himself.  “I guess I’d better not say anything about it.  They’d make fun of me.  I know it’s all right to take her, or I wouldn’t do it.  Besides, if she knows the captains she can be of considerable aid to me.  Queer, though, for Larry Dexter, who used to rush copy, to be hunting for a missing millionaire in company with his pretty daughter.”

It was odd, but no other line of activity is so filled with strange surprises, or brings about such a variety of work, as being a newspaper reporter of the first class.

Larry struck several snags when he attempted to get information at the sub-station.  In the first place none of the officials in charge would give him any news about the envelope unless he got an order from the New York postmaster himself.  The government has very strict regulations in regard to giving out information about mail matter.  But Larry was not daunted.  He telephoned to Mr. Emberg, and the forces of the newspaper were set to work.  Certain political wires were “pulled,” and, as there were on the Leader men to whom the postmaster was under obligations, that official gave the clerks at the sub-station permission to tell Larry whatever he wanted to know.

“Sorry we had to have so much red tape about it,” the sub-station agent said, when Larry came back with the magical paper that opened the mouths of the subordinates.

“Oh, that’s all right,” the reporter said.  “I know how it is.  Now, what I want to know is, in what box was that letter posted?” and he held out the envelope Grace had given him.

“Rather hard to say,” spoke the head clerk.  “I’ll show it to all the carriers who are in now, and later to those who come in during the afternoon.  They may recognize it.  It’s a little out of the run of ordinary envelopes we get in this section of the city.”

One after another several carriers scanned the envelope.  All shook their heads, until it came to an elderly man.  As soon as he saw the envelope he exclaimed: