Ned pointed to the dark corner.

“You’d better come away,” warned the boy.

“We are here to investigate,” Ned replied, almost impatiently.

“Then investigate with a bomb, or with a cannon,” advised Jimmie.

“No time for that,” came the reply. “The conditions which exist now may not exist in an hour’s time. It is now or never.”

Moving forward, Ned saw a faint finger of light cutting the shadows in the corner Jimmie had pointed out. Jimmie saw it at the same instant.

“I’ll bet they’ve got a blacksmith shop down there,” he said.

There was no opening in the great stone slabs of the floor through which a man might make his way—only the crevice through which the ray of light came. Ned turned his attention to the wall to the south.

Behind a luxuriant growth of vines he saw another glimmer of light, and in a moment stood looking down a narrow stairway, at the distant end of which were numerous lines of red flame. Jimmie, looking over Ned’s shoulder, uttered a muffled exclamation.

“Looks like a door made out of red-hot bars,” he said.