ar shelf, where, in the shadow, was a huddle of brown fur and a bit
of crust. It fell as they watched, and the "plop" of the soft body upon
the floor sounded loud in the silent room.

"The law of compensation," said Professor Eddinger. "Two sides to the
medal! Darkness and light--good and evil--life ... and death!"

* * * * *

The young man was stammering. "What do you mean?--a death ray evolved?"
And: "What of it?" he demanded; "what of it? What's that got to do with
it?"

"A death ray," the other agreed. "You have dreamed, Avery--one must in
order to create--but it is only a dream. You dreamed of life--a fuller
life--for the world, but you would have given them, as you have just
seen, death."

The face of Avery was white as wax; his eyes glared savagely from dark
hollows.

"A rat!" he protested. "You have killed a rat ... and you say--you
say--" He raised one trembling hand to his lips to hold them from
forming the unspeakable words.

"A rat," said the Professor--"or a man ... or a million men."

"We will control it."

"All men will have it--the best and the worst ... and there is no
defence."

"It will free the world--"

"It will destroy it."

"No!"--and the white-faced man was shouting now--"you don't
understand--you can't see--"

The lean figure of the scientist straightened to its full height. His
eyes met those of the younger man, silent now before him, but Avery knew
the eyes never saw him; they were looking far off, following the wings
of thought. In the stillness the man's words came harsh and commanding--

"Do you see the cities," he said, "crumbling to ruins under the cold
stars? The fields? They are rank with wild growth, torn and gullied by
the waters; a desolate land where animals prowl. And the people--the
people!--wandering bands, lower, as the years drag on, than the beasts
themselves; the children dying, forgotten, in the forgotten lands; a
people to whom the progress of our civilization is one with the ages
past, for whom there is again the slow, toiling road toward the light.

"And somewhere, perhaps, a conquering race, the most brutal and callous
of mankind, rioting in their sense of power and dragging themselves down
to oblivion...."

* * * * *

His gaze came slowly back to the room and the figure of the man still
fighting for his dream.

"They would not," said Avery hoarsely; "they'd use it for good."

"Would