"I agree with you," chimed in Ralph.
"What, Ralph, my boy, you here?" exclaimed the professor. "Why, you were far in advance. How do you come to be with us now?"
As modestly as he could, Ralph related how he had turned back into the black tunnel.
"That was bravely done, bravely done, my boy," exclaimed the professor warmly.
Even in the darkness Ralph colored with pleasure, as Walt added his praise to the scientist's.
Soon after they started for the entrance of the tunnel once more, Ralph having told them of his discovery of the shaft.
"Possibly there are steps cut in it. Let us hope so," said the professor. "If there are not, we shall be as badly off as before, for we cannot get back through the tunnel."
"No," said Ralph with a shudder, "I would not face the horrors of the place again for a whole lot."
A careful investigation of the shaft soon revealed, to their great joy, that a flight of steps had indeed been cut in it, doubtless to enable the old Mission dwellers to ascend and descend from the surface of the earth when they desired.