Their efforts to open it in an ordinary manner were wasted; but while they sought to do so they were surprised and interested to hear a strange thumping sound issuing from some part of the building just beyond that very door.
As they paused to speculate concerning the meaning of that thumping, another startling and disagreeable thing happened.
In the hall behind them there was a flash, and the loud and deafening report of a pistol smote upon their ears. At the same instant a bullet clipped past Dick’s ear and struck the candle in his hand, cutting it off close to the top and extinguishing it.
Buckhart turned in a twinkling and answered the shot by firing blindly back into the hall.
The flash of his pistol blinded Brad, but Dick—who had also wheeled and was slightly to one side—plainly saw a man spring through a doorway and vanish from view.
Once more snatching out his own revolver and warning Buckhart against shooting him by mistake, Merriwell darted back into that hall and followed the man through the doorway.
He discerned a dark figure just slipping out through the very window by which the two boys had entered the mill.
Although he was tempted to fire on the fleeing man, Dick restrained the impulse, permitting the unknown to escape.
“He’s gone,” he explained, in answer to the eager questions of the Texan, who had followed closely. “Let him go. I’m for finding out as soon as possible the meaning of the thumping sounds we heard beyond that immovable door. Let’s look for something with which we may batter down the door.”
In the mill section of the building they discovered a huge, rusty hammer, and with this they returned and attacked the door, Dick having relighted his candle.