"I came as fast as I could," Larry responded. "Where is the letter?"

Grace held out to him a small piece of paper. On it was but a single line of writing. It read:

"Am well. Have to stay away for a time. Don't worry. Will write again."

It was signed with Mr. Potter's name.

"Are you sure it's from your father?" asked Larry, thinking some cruel person might be trying to play a joke, or that some enterprising reporter had sent the message for the sake of making news. Such things are sometimes done by New York newspaper men, though their city editors may know nothing about it.

"I couldn't mistake father's writing," replied Grace. "Mamma knows it is from him, and she is much happier. But we can't imagine why he has to stay away."

"When did you get this, and how did it come?" asked the reporter.

"The postman brought it a little while ago."

"Where is the envelope?"

Grace handed it to Larry. An inspection of the post-mark showed that it had been mailed in New York in the vicinity of sub-station Y, which was on the East Side. It might have been dropped in one of the many street boxes from which collections were made for that particular office, or it might have been mailed in the station itself.

"Not much to trace him by," said Larry. He looked at the envelope again and saw that there was a small ink blot on the lower left-hand corner, and that the corner where the stamp was affixed was smeared as if with some sticky substance.

"Any one would think you were a detective," said Grace, as she watched Larry examining the envelope. "What does it matter now? We are sure father is alive, for that note was posted yesterday. That has made mother and me happy. Of course we want to find him, but I don't see how you can by that letter. I thought you'd like to know about it to make a little item for the paper, and I wanted to repay you for your kindness to mother and me."

"I haven't done anything," Larry replied. "I am only too glad to be of service to you. But I may be able to find out something by this envelope."

"I don't see how."

"Will you let me take it to the sub-station?"

"Of course. But what good will that do?"

"I want to ask the sorters and clerks in charge if they remember having handled it. I may find the carrier who brought it in from the box, and he can tell in what locality it was."

"But how can they remember when they must handle thousands of letters every day?"

"Perhaps they cannot, but it is worth trying. You see in that section of the city are mostly foreigners, who write a peculiar hand, and use stationery anything but clean or of this quality. This envelope and paper are of an expensive kind."

"Yes, they are some father had made to order for his private correspondence. I did not know he took any to Europe with him, but he must have."

"It may be that a letter carrier or mail sorter took enough notice of the envelope to remember it," Larry went on. "Besides there is a small blot on it, and the way in which the stamp is put on shows that some glue or paste was applied to the envelope. Probably he used an old stamp which had no mucilage on. To make it fast to the envelope your father, or whoever posted the letter, would have had to use some sticky substance, and, in doing so, he has put it on a little too thick. Some spread out from under the stamp and soiled the envelope.

"Of course the sorters and carriers don't pay much attention to the pieces of mail, except to see that they are properly stamped and addressed, but it's worth trying. This envelope would attract attention if anything would."

"And you are going to use that for a clue?"

"I'm going to try. It may be useless. If we can find in what particular locality it was mailed we can have the police keep a watch for your father. He may mail other letters there."

"But my father is not a criminal. Why should the police watch for him so particularly. They are keeping a general lookout now, but I wouldn't like to think they were lying in wait for him."

"It's the only way to find him," said Larry. "Of course it's unpleasant, but there is evidently some mystery here, and that's the best way to clear it up."

"But he says he has to stay away for a while," argued Grace. "Maybe he wouldn't like to be found."

"Of course that point has to be considered," Larry admitted. "But I take it you and your mother want to find your father, or be in a position to communicate with him."

"Oh, we do!" exclaimed Grace.

"Then we'll have to ask the police to help us. There is no disgrace in it. Everyone knows your father is honorable, and if he wants to disappear that's his business. It is also perfectly right for you to try to find him, for----" and Larry stopped.

"Well, for what?" asked Grace, seeing the reporter hesitate.

"I don't want to alarm you," Larry went on, "but I was going to say that there is no way of telling but what some one may have imitated his writing and forged his name."

"I am sure that is my father's writing," the girl said, earnestly.

"Of course I may be mistaken. I hope not. I prefer to believe that note is from him. It makes me happier."

"Of course there is only the barest possibility that this note is not from your father, but we can take no chances. That is why I want to make a systematic search, beginning at the sub-station."

"And where will it end?" asked Grace.

"I don't know. But after that I am going to the steamship piers of all the lines that ply between here and Italy."

"What for?"

"I want to see if the captain of any of the steamers recalls any man answering your father's description having come over with him.

He must have sailed on some steamer, as he is in this country, if that note is from him."

"That's a good idea," commented Grace. "How I wish I could help you.

Couldn't I? Couldn't I go around with you--that is to the steamer piers? I've crossed the ocean several times, and I know some of the captains of the Italian lines."

"Maybe that would be a good idea," said Larry, secretly delighted with it. "You can come with me to-morrow. I will go to the sub-station now, and will let you know what I learn. Then we will make a tour of the piers. You'll be of great a.s.sistance to me, for I know very little about steamers."

"I'm so glad!" exclaimed Grace. "It has been terrible to sit here day after day and only wait! I wanted to do something to help find father. Now there is a way! I wish I was a boy--no, I'd rather be a reporter; they can do so many things," and Grace laughed more heartily than at any time since her father had disappeared.

"I'm afraid you give us too much credit," replied Larry. "We do our best, but we don't always get results. Are you sure your mother will let you go?"

"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 a.s.sistant. 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 a.s.signment 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."