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.
"Nobody touched the doors!" ejaculated Stanley. "It must be some of the ghost's work."
"Nonsense!" answered Dick sharply. "Somebody shut the doors—and locked 'em," he added after trying both. "Hi, you!" he called. "Open these doors, and be quick about it!"
"Thou fool, to come here!" exclaimed a hollow voice from the other side of the doors.
"It's the ghost! I said it was!" said Stanley.
"It's somebody fooling us," answered Tom. "Open the door, or we'll smash it down!" he added in a loud voice.
