We went out into the corridor again, across which was the small room insulated from all aerial vibrations. In the corridor a figure was standing—the one other member of the Brende household—the maid-servant, a girl about Elza's age. I knew her well, of course, but this evening I had forgotten her existence. She was standing in the corridor. Did I imagine it, or had she been gazing up at the mechanism ten feet above the floor—the mechanism controlling the insulated room?
"You wish me, Miss Elza? I thought I heard you call."
"No, Ahla, not 'til later."
With a gesture of respect, the girl withdrew, passing from our sight down the incline which led to the lower part of the house.
It was a very small incident, but in view of what was transpiring, it gave me a shock nevertheless.
For Elza's maid was a Venus girl!
CHAPTER III
Spy in the House
The insulated room was small, with a dome-shaped ceiling, no windows, and but one small, heavy door through which we entered, closing it carefully behind us.