m you will find
brains which excel any to be found on the surface of the earth, since
we two are below. Already I have learned much from them. You, Mr.
Carnes shall be taught to pilot an airplane. When my cohorts go forth
from the realms of the Selom to establish the rule of Russia, you will
be piloting one of the planes. Your first task will be to learn to
fly."

"I refuse to do anything of the sort!" said Carnes.

"I will not be ready to have your flying lessons started until
to-morrow," replied the Russian, "and you will have until then to
reconsider your rash decision. It will be much easier for you if you
obey my orders. If you still refuse to-morrow, you will pay a visit to
the laboratory of the Selom. When you return your lessons will be
started. You will now be taken to your cell. I have use for Dr. Bird
this afternoon."

"I won't leave Dr. Bird and that's flat!" exclaimed Carnes. Dr. Bird
interrupted him.

"Go ahead, Carnesy, old dear," he said lightly. "You might just as
well toddle along under your own power as to be dragged along. You
have a day for reflection, in any event. I daresay I'll see you again
before they do anything to you."

Carnes glanced keenly at the doctor's face. What he saw evidently
reassured him for he turned without a word and walked away. The light
grew gradually dimmer until darkness again reigned in the cavern.

"Come, Doctor," said Saranoff's voice. "We have work to do."

* * * * *

Carnes sat alone in his cell for hours. The darkness and loneliness
wore on him until he felt that his nerves would crack. Not a sound
came to him. He threw himself on one of the beds and plugged his ears
with his finger tips in an attempt to keep the silence out. Then a
cheerful voice sounded in the cell and a friendly hand fell on his
shoulder.

"Well, Carnesy, old dear," said Dr. Bird, "have you been lonesome?"

"Dr. Bird!" gasped Carnes in tones of relief. "Are you all right?"

"Right as can be. I learned a lot this afternoon. For one thing,
you're going to start flying lessons to-morrow and you're going to do
your best to become an expert pilot in a short time. It is the only
thing to do."

"And fly a plane for Saranoff?"

"I hope not. The only way to avoid that very thing is to keep your
mentality unimpaired so that I can call on you for help when I need
it. If the Selom operate on you, you will be useless to me."

"Operate? What do you mean?"

"I'