"Did you get here all right?" asked Ned, eagerly, but a sight of Frank's sad face sobered him. The two boys were told what had happened.

"I don't know what to do," Bart admitted as he and his two chums went outside, leaving Frank with his father.

"I've got an idea!" exclaimed Fenn eagerly. "I saw by that paper which Frank dropped, that Dr. Robertson was spending a few days at Forest Villa. That's the next place to Mr. Armstrong's house."

"Who is Dr. Robertson?" asked Ned.

"Why he's a great specialist on diseases of the brain. Why not go to him, and ask him to come and see Frank's father? I'm sure he would if we told him all the facts."

"Say!" cried Bart. "That's a fine idea! Hurry off and see if the doctor will come. If he wants pay we can give it to him."

But Dr. Robertson did not want any fee, when Fenn had breathlessly explained the circ.u.mstances to him. He questioned the boy closely, and then, taking his medicine case with him, set out through the woods. He was on his vacation, he explained, but he never missed a chance to study or treat a brain disease, and he was very much interested in Mr.

Roscoe's case.

Dr. Robertson sent all the boys out of the tent, and told them to stay away while he examined the patient. How anxiously they waited for the verdict, Frank most of all! Was the case a hopeless one? At last the doctor came out. He was smiling, and the boys took that as a good sign.

"You can come in, boys," he said.

"Is he--can you--will he--" stammered Frank.

"He will get well, if that's what you mean," said Dr. Robertson. "He is much better now. The fact is," he went on, "his fits of insanity were only temporary, and they were caused by a drug, which was administered to him in his food. He ate something at the sanitarium just before you rescued him, and this last time the drug began to work as soon as he heard that donkey bray. The fit has pa.s.sed now, and if he doesn't get any more of the drugged food he will probably have no more insane spells."

"Oh, I'm so glad!" cried Frank, sinking on his knees at the side of the cot on which his father lay.

Mr. Roscoe opened his eyes.

"Frank! My boy!" he murmured. Then he dozed off again.

The doctor stayed at the tent until noon, and left some medicine, saying he would call again in the evening. Soon after the medical man had left Mr. Roscoe awakened. He declared he was much better, and in talking of his case he said he noticed that the strange spells came over him soon after he had eaten something. At other times he was as clear-headed as he had ever been.

In a few days, under the treatment of Dr. Robertson, Mr. Roscoe had fully recovered. It was thought best to keep him at the camp for a few days, as the rest would do him good.

"Then you'll come away with me and we'll make a home for ourselves,"

said Frank.

"Why not stay with your Uncle Abner?" asked Mr. Roscoe.

Frank told of his suspicions, that his uncle was in the plot with the men who held Mr. Roscoe a prisoner.

"No, you're wrong," said Frank's father. "Your uncle was deceived by the men. I understand it all now. He thought I really was insane, and he was doing what he imagined was right to keep me in the sanitarium. He was trying to hold the property for you. Those men fooled him, but now we will get the best of them."

Mr. Roscoe's theory proved correct, when a little later the boys broke camp and went home. Mr. Dent was much surprised when told the facts in the case, and confirmed what Frank's father had said. The property was gotten away from the men, and the plotters had to flee to escape arrest.

Dr. Hardman was among them, and his sanitarium was taken in charge by the authorities, for he had many persons there who were really insane.

"And so that was Frank's secret," remarked Bart, one afternoon as the four chums were talking together over the strange case. "I would never have suspected it."

"I hardly believed it myself, at times," said Frank.

"Well, we had some fun with the donkey, anyhow," put in Ned. "That was about the only comic happening during our camping."

"I guess we've had enough of adventures to last for several vacations,"

spoke Frank. "I'm willing to settle down to a quiet life."

But a quiet life was not in store for the four boys, and why will be related in another volume, to be called "Fenn Masterson's Discovery." In that tale we shall learn the particulars of an interesting voyage on the Great Lakes, and the particulars of a revelation which came to Stumpy when he least expected it.

"Frank, I suppose you are happy now you have your father with you," said Bart one day.

"Happy?" repeated Frank, with a little lump in his throat. "I am more than happy. Why, I feel as if the whole world was nothing but pure sunshine!"

"Well, we all rejoice with you," came from Ned.

"Indeed we do!" added Fenn.