The boys made an ineffectual search for those who had played the trick. They soon discovered that the bags had been thrown through the ventilator, but, by the time a committee of investigation had gone to the loft, the four chums were far away.
"We'll not say anything about this at school, Monday," Ned remarked as the chums prepared to separate that night. "Let it come from the other fellows."
"Oh, it will be town talk by to-morrow," declared Frank, as he started off down the road toward his uncle's house.
Mr. Dent's residence was about a mile outside of Darewell. The road leading to it was well lighted up to within half a mile of the Dent place, and then the lamps were few and far apart. Frank hurried on, thinking of many things besides the trick of the mice, for he had a real trouble, and one he had not yet shared with his chums. It was bothering him, and had been for some time. He wished he had someone he could take into his confidence.
As he neared his uncle's house he noticed there was a light in the sitting room. This was unusual, as his uncle and aunt were in the habit of going to bed early. They left no light for Frank, who had a key to the front door, and who carried matches to light the lamp always left on a table for him.
"I wonder if any one is sick?" the boy thought, as he approached the house.
He turned up a side path, as he wanted to get a drink at the well before going to bed, and the water in the house was not likely to be fresh. As he advanced cautiously through the darkness he heard voices, coming, evidently, from the direction of the front porch. Frank halted, and, as he did so, he heard his uncle's tones. Mr. Dent was saying:
"Of course it's too bad, but if he's violent, there's only one thing to do."
"That's all," the voice of a man replied. "We will have to keep him in the sanitarium for a while yet. I am just as sorry about it as you are. But we must not let the boy know. It might have a bad effect on him."
Frank started. All his troubles seemed to come freshly to his mind. He knew the man talking to his uncle had something to do with them, and he resolved to find out more about the matter. He remained silent, hoping to hear additional talk, but the two had concluded their conversation, and the stranger could be heard walking down the gravel path toward the front gate. That was what the light had meant. Mr. Dent had received a visitor, and Frank determined to find out who it was.