From underneath the door came a little puff of smoke.

There was a queer sense of heat of which both men were simultaneously conscious.

Down in the street arose a chorus of warning shouts, increasing momentarily in volume.
Quest threw open the door and closed it again at once.
"The place is on fire," he announced briefly.

"Pull yourself together, man.

We shall have all we can do to get out of this." Craig turned to the door but staggered back almost immediately.
"The stairs are going!" he shrieked.