Estelle followed gingerly and in a moment they were safely below. The
corridor was quite empty.

"When the crash came," Estelle explained, her voice shaking with
the reaction from her fear of a moment ago, "every one thought the
building was coming to pieces, and ran out. I'm afraid they've all
run away."

"They'll be back in a little while," Arthur said quietly.

They went along the big marble corridor to the same western door,
out of which they had first gone to see the Indian village. As
they emerged into the sunlight they met a few of the people who
had already recovered from their panic and were returning.

A crowd of respectable size gathered in a few moments, all still
pale and shaken, but coming back to the building which was their
refuge. Arthur leaned wearily against the cold stone. It seemed to
vibrate under his touch. He turned quickly to Estelle.

"Feel this," he exclaimed.

She did so.

"I've been wondering what that rumble was," she said. "I've been
hearing it ever since we landed here, but didn't understand where
it came from."

"You hear a rumble?" Arthur asked, puzzled. "I can't hear anything."