The result of civilization now became apparent. The first natural feeling of terror passed, the reaction came, and both Nattie and the young Japanese were able to discuss their situation with more or less calmness.
"This is dreadful, simply dreadful," said the latter; "but we must face it and see what can be done to save ourselves."
"What was it, an earthquake?"
"Yes, but not much of a shock. We felt it down here; above ground it was simply a wave of minor strength."
"But others may come, masters," exclaimed the porter, with chattering teeth.
"You are right. We must hasten back the way we came. The shock has barred our passage in this direction; only the castle exit remains to us."
There was little time lost in commencing the retreat. Grasping hands the three staggered along the tunnel floor, walking, running, and even crawling at times. The dust that had filled the excavation immediately after the earthquake soon settled, and the breathing became easier.
Presently Nattie stopped.
"What is the matter?" anxiously asked Mori.