w
days. The Selom are sincere in their desire to help the upper world.
They feel great pity for mankind in view of the conditions Saranoff
has described to them. When the king returns. I plan to make a direct
appeal to him. In the meantime, go on with your flying lessons. How
did you make out to-day?"

* * * * *

The second day was a repetition of the first, as were the third and
fourth. A week passed before Dr. Bird entered the cell in evident
excitement.

"Has Hanac brought our evening food yet?" he asked anxiously.

"No, Doctor."

"Good. Take this light. As soon as he enters throw the light full on
him and hold him until I work on him. We've got to make our escape."

"Why?"

"The king is due back to-morrow. Saranoff is frightened at the good
impression I have made on the Selom. He is supreme in the monarch's
absence, so he plans to operate on both of us before he returns. He is
afraid to allow me to see the king with an unimpaired intellect and
memory. Shh! Here comes Hanac." The door to their cell opened
noiselessly. When the mole who brought their food was well inside,
Carnes turned on the tiny flashlight. The mole dropped on all fours
and tried to turn its back. Dr. Bird sprang forward. For an instant
his slim muscular fingers worked on the mole's neck and shoulders.
Silently the animal sank in a heap.

"Come on, Carnes," cried the doctor. "Turn off the light."

"Did you kill him, Doctor?" asked Carnes as he raced down a pitch dark
corridor at the scientist's heels.

"No, I merely paralyzed him temporarily. He'll be all right in a day
or so. Turn here."

* * * * *

For ten minutes they ran down corridor after corridor. Carnes soon
lost all track of direction, but Dr. Bird never hesitated. Presently
he slowed down to a walk.

"It's a good thing I have a good memory," he said. "I planned that
course out from a map, and I had to memorize every turn and distance
of it. We are now behind your flying hall and away from any of the
regular dwellings of the Selom. Straight west about four miles is one
of the time-ray machines with a guard over it. Aside from them, there
isn't a mole between here and Detroit."

"What are we going to do, Doctor?"

"Keep out of their way and avoid recapture if we can. If we merely
wanted to escape we would try to get possession of that time-ray
machine and open a road to the surface. However, I am not content w