aboratory.

* * * * *

"Vic! Hope!" I pounded as hard as I could, shouting their names. There
was no response.

"Is there another key, Perrin?" I snapped.

"No, sir; none that I know of. The master was mighty fussy about his
workroom."

"Can we get in through the windows?"

"No. They're barred, if you remember rightly, and fitted with this
frosted glass, so you can't see in, even."

"Then get me an ax!" I commanded. "Quick!"

"An ax?" hesitated Perrin.

"An ax--and be quick about it!"

Perrin mumbled a protest and hurried away. I turned to Mrs. Perrin, who
had come up to determine the result of my shouting.

"How long is it since Miss Hope went in there?"

"How long, sir? I'd say about twenty minutes before you came. Maybe
twenty-five. I wasn't paying any particular attention, sir. She just got
the key and went in. After a few minutes I heard something buzzing in
there, and I thought maybe Mr. Butler was showing her some new gadget of
his, like he was always doing. Then there was a telephone call for him,
and I couldn't make neither of them answer; that's when Mr. Perrin and I
began to get worried."

"I see." Perrin came hurrying up with the ax, and I motioned them aside.
I swung the ax, and the head of the weapon crashed against the lock. The
knob dropped to the floor with a clatter, but the door gave not at all.

I brought the ax down again, and something cracked sharply. The third
blow sent the door swinging wide.

Cautiously, fearing I know not what, I entered the familiar room.
Nothing, apparently, had been disturbed. There was no sign of disorder
anywhere. The blankets on the narrow cot in the corner of the room had
not been unfolded.

But neither Vic nor Hope were anywhere in sight.

* * * * *

"You and Mrs. Perrin stay there by the door," I suggested. "I don't know
what's wrong here, but something's happened. There's no need for all of
us entering."

My second glance around the room was more deliberate. To my right were
the big generators and the switchboards, gleaming with copper bus-bar,
and intricate with their tortuous wiring. Directly before me was the
long work-bench that ran the full length of the room, littered with a
dozen set-ups for as many experiments. At my left was a sizable piece of
apparatus that was strange to me; on a small enameled table beside it
was a rather large sheet of paper, weighted down with a crack