more menthium than Professor Williams did
this evening especially as I will extract your entire supply and
reduce you to permanent idiocy. I will have no mercy on you as I have
on the others I have operated on."

Dr. Bird blanched in spite of himself at the ominous words.

"You have the whip-hand for the moment, Slavatsky, but my time may
come--and if it does, I will remember your kindness. I saw your
operation on Professor Williams this evening and know your power. I
also know that you stole the idea and the method from Sweigert of
Vienna. I saw you inject the fluid you drew into Willis' brain. Shall
I tell what else I saw?"

It was the dwarf's turn to blanch, but he recovered himself quickly.

"Into the chair with him!" he roared.

* * * * *

Three of the men grasped the doctor and forced him into the chair and
Slavatsky started the generator. The violet light bathed Dr. Bird's head
and he felt a stiffness and contraction of his neck muscles, and as he
tried to shout out his knowledge of Slavatsky's treachery, he found that
his vocal chords were paralyzed. Through a gathering haze he could see
Carson approaching with an anesthesia cone and the sweet smell of lethane
assailed his nostrils. He fought with all his force, but strong hands held
him, and he felt himself slipping--slipping--slipping--and then falling
into an immense void. His head slumped forward on his chest and Slavatsky
shut off the generator.

"On the table," he said briefly.

Four men picked up the herculean frame of the unconscious doctor and
hoisted him up on the table. Carson seized his head and bent it
forward and the dwarf took from a case a syringe with a five-inch
needle. He touched the point of it to the base of the doctor's brain.

"Slavatsky! Look!" cried Frink.

With an exclamation of impatience the dwarf turned and stared at a
disc set on the wall of the cave. It was glowing brightly. With an
oath he dropped the syringe and snapped a switch, plunging the cave
into darkness. A tiny panel in the door opened to his touch and he
stared out into the light.

"Soldiers!" he gasped. "Quick, the back way!"

As he spoke there came a sound as of a heavy body falling at the back
of the cave. Slavatsky turned the switch and flooded the cave with
light. At the back of the cave stood Operative Carnes, an automatic
pistol in his hand.

"Open the main door!" Carnes snapped.

* * * *