worked out together. A second switch clicked under his
fingers. From the lense of the focusing machine shot the reverse
atomic beam. As it struck the center of the square it turned a bright
vermilion. For several seconds it played upon empty space, then the
miracle unfolded before their eyes.

Something like a glass sliver reflected the beam. It grew and enlarged
under their startled eyes until it had achieved its former size, then
the power that had brought it back switched itself off automatically.

Together both men examined the test tube. It appeared in no way
harmed, nor did it feel either warm or cold from its trip through the
elements.

"It works!" marveled Danzig. "Let's try it again with something
larger."

"I've got a better idea," said Carruthers, rising to his feet. He
crossed the laboratory and went to another part of his rooms.
Presently he returned holding a small pink rat in his hands. The
rodent was young, having been born only a week before. "Now we'll see
what happens."

"Oh, it's torture to the poor thing," burst out Nanette.

"It won't hurt it," growled Karl. "Aaron knows what he's doing."

Carruthers placed the little rat in the center of the square. It lay
there, very quiet and unblinking. Again the switches clicked as the
contacts were closed.

Came once more the beam of amber colored light followed closely by the
violet. The rat dwindled to the size of an insect, then disappeared
into space. The three watchers held their breaths. Carruthers' hand
trembled the least bit as he threw on the switch controlling the
animal's return to the world.

* * * * *

A vermilion shaft of light pierced the semi-darkened rooms. The animal
had been gone from sight not more than a minute. Abruptly something
grayish white unfolded in the reflector's beam. It rapidly expanded
under three pairs of bulging eyes--not the small, pinkish rat that had
disappeared but sixty seconds previous, but a full grown rat, scarred
and tailless as if from innumerable battles with other rats.

As the current clicked off Aaron Carruthers bent forward. Too late.
The rat scurried from the laboratory with a squeal of alarm.
Carruthers returned to his seat before the atomic machine and sat
down. His face was worried. Dark thoughts stormed his reason. The rat
he had placed within the atomic ray had aged nearly two years during
the minute it was out of mortal sight. Two years!

He pulled a pad fr