"Humph!"
"So he is your Uncle Wilbur," went on our hero, after a pause, and he turned a look of sympathy at Nat as he spoke.
"Who told you that?"
"You called him Uncle Wilbur."
"I--I guess you are mistaken," stammered Nat, growing red in the face.
"No, we heard you as plain as day," put in the senator's son.
"You haven't any right to pry into my affairs, Roger Morr! You nor Dave Porter either!"
"Perhaps not," answered Roger.
"Look here, Nat, if we can help you we'll do it," came from Dave. "I suppose, if that man is your uncle, you wish to get him back to the--er--the sanitarium as quickly and as quietly as possible; is that so?"
"Wouldn't you want to do that, if he was your uncle?" asked the money-lender's son, flushing deeply.
"Certainly. But it looks, now, as if you couldn't do it alone."
"I might have done it, if you hadn't come up and queered my game."
"He didn't see us until he ran out of the cabin," said Roger. "He just got a wild streak on, that's all. I don't think you could have managed him alone. He wouldn't let you tie him up with that rope."
"Well, he's gone, that's sure," grumbled Nat. "I'm going back to the cabin for my valise."
"He may come back," suggested Dave.
"I don't think so. But I'll wait and see. I hung around once for him--on that island--but he never came back. It isn't often he visits the same spot twice. That's the reason the authorities around here haven't caught him."
"What is his name, Nat?"
"Wilbur Poole, if you must know. He is my father's half-brother."
"Where did he come from?"
"From the Blossmore Sanitarium, in New York state. It's a private place, near Lake Erie. He lost a lot of money several years ago in a speculation in Sumatra tobacco and that made him crazy, and that is why, I suppose, he calls himself the King of Sumatra."
"Did you know he was missing when you heard of the wild man?" questioned Dave, with interest.
"No, I did not, for the sanitarium people did not notify us that he had gotten away. I suppose they thought he would stay near the institution and that they would be able to get him again. I can't imagine what brought him away out here, excepting that I went to see him once, when he was somewhat better, and I told him about Oakdale and our school. I knew he called himself the King of Sumatra, and that is why I got interested in the wild man as soon as I heard you mention that name. Then, when the handkerchief was found, I was sure the man was my uncle."
"And you put the hole in the handkerchief," said our hero.
"Yes, because--well, I didn't want folks to find out from the Blossmore authorities that the man was my uncle," answered Nat, casting down his eyes. "I thought I might be able to catch him and send him back on the quiet. I didn't want the whole school talking about it."
"I can understand your feelings, Nat," said our hero, kindly. "And if I can help you in the matter, I'll do it."
"I suppose you'll tell everybody he's my uncle," came bitterly from the money-lender's son.
"No, I won't. But I think Doctor Clay ought to know it."
"And what of your folks?" asked Roger. "Do they know?"
"I sent my dad a letter about it last week. But he is away on business, so I don't know when he'll get it or what he'll do. I didn't let the Blossmore folks know because I don't think my uncle ought to go back to that place. He ought to be put in an institution where they are more strict, so he can't get away again."
"You are right there," said Dave.
"Nat, don't you know it is highly dangerous to allow that man at large?" asked the senator's son, after a pause, during which the three boys turned their footsteps towards the island cabin.
"Oh, I don't think he is as dangerous as some folks imagine," was the reply. "He has never actually harmed anybody yet. But he scares 'em."
"He may have committed some deeds of which you know nothing."
At these suggestive words from the senator's son Nat turned pale.
"What do you mean? Have you heard anything, Roger?"
"I hate to hurt your feelings any further, Nat, but I must be honest with you. Dave and I have an idea that he was the one who blew up the dining-room of Sparr's hotel."
"Oh, impossible!"
"What Roger says is true," said Dave, gravely. "I am sorry for you, Nat, but that is the way it looks to us. He was seen around the old stone bridge when it was blown up, and around the shanty where the dynamite was kept, and he has been in Oakdale several times, so we have heard."
"Oh, he wouldn't do such a thing! He couldn't!" cried the money-lender's son, in genuine distress.
"An insane man is liable to do anything, Nat," said Roger. "Why, he might have set off that dynamite without realizing the consequences. The best thing we can do is to organize a regular search for him, and round him up as quickly as possible."
"I suppose that is so," groaned Nat. "But, oh, how I do hate the exposure!"
"You mustn't take it too hard, Nat," said Dave. "Remember, neither you nor your family are responsible for his condition of mind."
It did not take the three students long to reach the little cabin. While Nat was packing up the things he had brought along, Dave and Roger looked over the place. The wild man had had but few things, none of them worth mentioning. There was a newspaper and an old magazine, showing that Wilbur Poole occasionally indulged in reading.
"Hello, look here!" cried Roger, as he turned the magazine over. "Well, I declare!"
"What is it?" asked Dave and Nat, in a breath.
"Here's a picture, drawn in blue pencil. It is marked Fort, but it looks like Sparr's hotel."
"And look what it says!" cried Dave, eying the crude drawing. "'Powder House to be blown up'! That's the dining-room, as plain as day!"
"And down here it says, 'Dynamite will do it easily,' and signed, 'King of Sumatra.' Dave, he did it, and this proves it."
"It certainly looks that way, Roger."
"Let me see that drawing!" burst out Nat, and would have snatched it from Roger's hand had not Dave stopped him.
"You can look at it, Nat, but you must give it back," said our hero.
"What for? My uncle drew that and I have a right to it."
"No, I am going to hand this over to Doctor Clay and then to the Oakdale authorities. It may be needed to clear Phil, Ben, and Buster."
"Hurrah, Dave, that's the talk!" cried Roger, with sudden enthusiasm. "I didn't think of it, but that is just what is needed to clear 'em! We'll knock Jason Sparr's accusations into a cocked hat!"
"You let me see that drawing!" shouted Nat, making another grab for it. "I've got a right to it--if my uncle made it."
"You can look at it, but you can't handle it," said Dave, and he gave Roger a look that the senator's son well understood. Both knew that the money-lender's son could not be trusted with such an important bit of evidence.
The drawing was held up, but Nat was not permitted to get