til he recalls Stutsman from Callisto."

He paused in mid-stride, stood planted solidly on the floor.

"When Stutsman gets into the game," he said, "all hell will break
loose."

He took a deep breath.

"But we'll be ready for it then!"

_CHAPTER SIX_

"If we can get television reception with this apparatus of ours," asked
Greg, "what is to prevent us from televising? Why can't we send as well
as receive?"

Russ drew doodles on a calculation sheet. "We could. Just something else
to work out. You must remember we're working in a four-dimensional
medium. That would complicate matters a little. Not like working in
three dimensions alone. It would ..."

He stopped. The pencil fell from his finger and he swung around slowly
to face Manning.

"What's the matter now?" asked Greg.

"Look," said Russ excitedly. "We're working in four dimensions. And if
we televised through four dimensions, what would we get?"

Greg wrinkled his brow. Suddenly his face relaxed. "You don't mean we
can televise in _three_ dimensions, do you?"

"That's what it should work out to," declared Russ. He swung back to the
table again, picked up his pencil and jotted down equations. He looked
up from the sheet. "Three-dimensional television!" he almost whispered.

"Something new again," commented Greg.

"I'll say it's new!"

Russ reached out and jerked a calculator toward him. Rapidly he set up
the equations, pressed the tabulator lever. The machine gurgled and
chuckled, clicked out the result. Bending over to read it, Russ sucked
in his breath.

"It's working out right," he said.

"That'll mean new equipment, lots of it," Greg pointed out. "Wilson's
gone, damn him. Who's going to help us?"

"We'll do it ourselves," said Russ. "When we're the only ones here, we
can be sure there won't be any leak."

It took hours of work on the math machines, but at the end of that time
Russ was certain of his ground.

"Now we go to work," he said, gleefully.

In a week's time they had built a triple televisor, but simplifications
of the standard commercial set gave them a mechanism that weighed little
more and was far more efficient and accurate.

During the time the work went on they maintained a watch over both the
office of Spencer Chambers and the laboratory in which Dr. Herbert
Craven worked 16 hours a day. Unseen, unsuspected, they were silent
companions of the two men during many hours. They read what the men
wrote, read what wa