as
the motions of the stranger were and frantic as was her dodging, the
terrific forces of the tractor beams of the Interplanetary Vessel
held her in an unbreakable grip, and although she dragged the massive
_Sirius_ hither and thither, she could not escape.

"Hm ... m ... m," mused Brandon. "We seem to be getting nowhere fast.
How much power we using, Mac, and how much have we got coming in?"

"Output eighty-five thousand kilofranks," replied MacDonald, the first
assistant. "Intake forty-nine thousand."

"Not so good--can't hold out forever at that rate. Shove out the
receptor screens to the limit and drive 'em. They figure a top of sixty
thousand, but we ought to pick up a little extra from that blaze out
there. Drive 'em full out or up to sixty-five, whichever comes first.
Can't seem to crush his screens, so I guess we'll have to try something
else," and a thoughtful expression came over his face as he slowly
extended his hand toward another switch, with a questioning glance at
Westfall.

"Better not do that yet, Norman. Use that only as a last resort, after
everything else has failed."

"Yeah--I'm scared to death of trying it, and it isn't necessary yet. He
must have an open slit somewhere to work through, just as we have. I'll
feel around for it a while."

"Is there any way of hetrodyning the new visiray upon the exploring
frequency?"

"Hm ... m.... Never thought of that--it would be nice, too....
I think we can do it, too. Watch 'em, Quince, and holler if they start
anything."

He abandoned his desk and established the necessary connections between
the visiray apparatus and the controls of his board. There was a fierce
violet-white glare from the plate as he closed the switch, and he leaped
back with his hands over his eyes, temporarily blinded.

"Wow, that's hot stuff!" he exclaimed. "It works, all x, to the queen's
taste," as he donned his heavy ray-goggles and resumed his place.

After making certain that the visiray was precisely synchronized and
phased with the searching frequency, he built up the power of that
beam until it was using twenty thousand kilofranks. Then, by delicately
manipulating the variable condensers and inductances of his sensitive
shunting relay circuits, he slowly shifted that frightful rod of energy
from frequency to frequency, staring into the brilliant blankness of his
micrometer screen as he did so. After a few minutes of search the screen
darkened somewhat, revealing the