ured me that there would be at least one man on
"duty" in the military offices, though he would probably be asleep, and
two or three in the library proper and the projectoscope plant.

"We've got to put them out of commission," I said. "Did you bring the
'dope' cans, Wilma?"

"Yes," she said, "two for each. Here," and she distributed them.

We were now two levels below the roof, and at the point where we were to
separate.

I did not want to let Wilma out of my sight, but it was necessary.

According to our plan, Barker was to make his way to the projectoscope
plant, Blash and I to the library, and Wilma and Gaunt to the military
office.

Blash and I traversed a long corridor, and paused at the great arched
doorway of the library. Cautiously we peered in. Seated at three great
switchboards were library operatives. Occasionally one of them would
reach lazily for a lever, or sleepily push a button, as little numbered
lights winked on and off. They were answering calls for electrograph and
viewplate records on all sorts of subjects from all sections of the
city.

I apprised my companions of the situation.

"Better wait a bit," Blash added. "The calls will lessen shortly."

Wilma reported an officer in the military office sound asleep.

"Give him the can, then," I said.

Barker was to do nothing more than keep watch in the projectoscope
plant, and a few moments later he reported himself well concealed, with
a splendid view of the floor.

"I think we can take a chance now," Blash said to me, and at my nod, he
opened the lid of his dope can. Of course, the fumes did not affect us,
through our helmets. They were absolutely without odor or visibility,
and in a few seconds the librarians were unconscious. We stepped into
the room.

There ensued considerable cautious observation and experiment on the
part of Gaunt, working from the military office, and Blash in the
library; while Wilma and I, with drawn swords and sharply attuned
microphones, stood guard, and occasionally patrolled nearby corridors.

"I hear something approaching," Wilma said after a bit, with excitement
in her voice. "It's a soft, gliding sound."

"That's an elevator somewhere," Barker cut in from the projectoscope
floor. "Can you locate it? I can't hear it."

"It's to the east of me," she replied.

"And to my west," said I, faintly catching it. "It's between us, Wilma,
and nearer you than me. Be careful. Have you got any information yet,
Bl