"I want to tell you of what has happened here lately," (wrote Nat). "I have received two visits from a young fellow named Ward Porton, who is, I believe, a moving-picture actor, and the same fellow that you helped to rescue from a burning steam yacht. This fellow was in town once with Link Merwell, and then came here alone. He has been visiting a number of people who are well acquainted with you, and also visited the poorhouse here and talked to several of those in authority, and those who used to have the running of the poorhouse years ago, when you were an inmate there. This Ward Porton acted as if he had something of great importance on his mind, but what it was he would not tell, but he did let slip that it was something concerning you--that there was a big surprise in store for you. He also let slip that he, too, had been in a poorhouse when he was a little boy, and that he had never been able to learn where he had really come from. "I am writing this to put you on your guard in case he should show himself either at your camp or at the Wadsworth mansion after your return. I must confess that I don't like the fellow's manner, and I rather surmise he is laying pipes to play you some trick." Dave read this letter over several times, and was much perplexed. He had not forgotten what Link Merwell had said to him shortly after being captured, nor had he forgotten the fact that he had seen Link and Ward Porton in Crumville at the old Potts farm. "Those fellows are certainly up to something," our hero told himself. "Link said that I was not Dave Porter. Now, what did he mean by that? Those fellows must be hatching up some plot against me." "Dave, you look rather worried," remarked Phil, as he caught the youth reading the communication for the third time. "No bad news I hope?" "I can't tell whether it is or not, Phil," was the reply. And Dave handed the letter to his chum. "Phew! This looks like a mystery," was the comment of the shipowner's son. "Dave, do you think this had anything to do with what Link Merwell said when we caught him--that you were not Dave Porter?" "That's the way it looks to me, Phil." "But that's rank nonsense. We all know you are Dave Porter." "Well, I've always thought I was Dave Porter, ever since I met my Uncle Dunston out in those South Sea Islands." "Why of course you are! Don't you look just like your Uncle Dunston? This is some game, Dave." "I think so myself." "What are you fellows confabbing about?" asked Roger, walking up. "We're talking about a letter I just received," answered Dave. And then the senator's son also read the communication. "Say, this is a mystery and no mistake!" was Roger's comment. "And so Nat thinks that Ward Porton is mixed up in it, eh? That is strange." "What do you suppose he has to do with it, Roger?" questioned Phil.