lse--"

"He dies!" finished Clee, viciously thumbing into the air where the
invisible Xantra's neck was.

* * * * *

With all the intensity he could muster, Clee concentrated on one
simple, strong thought. He hardly heard the triumphant cries of the
slaves as they felt the blocking furniture give before their efforts;
all his energy was being expended in the will to get his thought
across.

"Tell those slaves to stop breaking in or you die!" he commanded.

The noises at the door continued. Either Xantra had not understood, or
else he was stubborn. He repeated his command and threat, and still
the crashing sounds came to his ears.

Desperate, he played his last card; and unconsciously his lips formed
the words of his next mental command, so that it was understood by the
breathlessly watching Vivian.

"_Tell them to stop!_" he willed. "_No more air till you do!_" And
with the words his fingers closed tightly over the other's throat.

The sounds at the door continued; for a moment the invisible form
between Clee's knees writhed violently--and then suddenly, almost
magically, a silence fell over the whole room. Clee had forced his
will on Xantra! He had made him stop the slaves!

And just in time.

Clee's fingers relaxed a little on the throat of the man beneath him.
He turned and said: "Quick, Vivian--find that anaesthetic!" A moment
later it was pressed in his hands. "Say when," he told the girl, and
held it beneath the nose of the helpless man. Xantra's head at once
fell back, and he heard Vivian telling him to stop. He pulled away the
bottle, corked it and stood up.

"Well, that's that," he said.

* * * * *

For a moment he was silent. Only the noises made by Jim in
strengthening the barricade at the door could be heard in the room.
Then he said, earnestly:

"I wish I could see you, Vivian--right now; but that'll have to wait.
I guess...."

A low laugh came from the place where the girl was standing. A hand
touched his arm, and he found himself being conducted into the alcove.
Vivian laughed again; said, teasingly, "What a stupid expression on
your face!" then commanded him to shut his eyes, and keep them shut.
He felt something being attached to his wrists; heard a coarse hum
that quickly rose in pitch until it passed the range of hearing. He
was caught up in a surprising exhilaration; he heard the hum again,
sliding down and down in pit