"It certainly has a vile smell!" exclaimed Stanley, making a wry face.
"That shows somebody has been here recently," was Dick's comment. "We had better be on guard if they are tramps."
"I can't stand that smell," said Tom. "I am going to get out."
The stuff in the fireplace, whatever it was, now burned up more brightly. It gave off a peculiar vapor that made the boys dizzy.
Tom turned to a door that led to the kitchen of the house. The door was shut, and he tried in vain to open it. The others were behind him and they, too, tried to open the barrier.
"Must be locked from the other side," said Tom. "Come on out the way we came in. Gracious! Isn't that awful stuff that is burning?" he added, for the vapor now filled the room completely.
In sudden alarm the four boys turned back toward the folding doors through which they had entered the dining-room. To their consternation, the doors were tightly shut.
"Who shut these?" asked Dick as he tried to open one of the doors.
"I didn't," said Sam.
"Neither did I," added Tom.