are we ourselves. Perhaps it would be more exact to say that their
scientific investigations and achievements have been along slightly
different lines. If such messages I sent them had come to our world
from another planet or dimension, how readily they might have been
misconstrued, ridiculed or ignored.' The Professor shrugged his
shoulders. 'But the beings in this sub-atomic world interpreted my
communications without difficulty.

"In no time we were conversing with one another through means of a
simplified code. I was soon given to understand that their scientists
and philosophers had long recognized the fact that their universe was
but an atom in an immeasurably greater dimension of existence; yes, and
had long been trying to establish contact with it.' The Professor's
voice fell. 'And not that alone: they were eager to cooperate with me
in perfecting a method of passing from their world to ours!

"'Yes,' he cried, 'much of what I have accomplished has been under
their advice and guidance; and they on their part have labored; until
now'--his eyes suddenly blazed into my fascinated face--'until now,
after months of intensive work and experiment, success is nigh, and any
day may see the door opened and one of them come through!'

"Gentlemen!" cried Milton Baxter, "what more is there to say? I
staggered from Professor Reubens' laboratory that afternoon, my head in
a whirl. That was on a Monday.

"'Come back Thursday,' he said.

"But as you know, Professor Reubens disappeared on a Wednesday night
before; and stranger still, his machines disappeared with him. In his
laboratory were signs of a struggle, and bloodstains were found. The
police suspected me of a guilty knowledge of his whereabouts, in short
of having made away with my friend. When I told somewhat of the
experiments he had been engaged in, spoke of the missing inventions,
they thought I was lying. Horrified at the suspicion leveled at myself,
I finally left Tucson and went abroad. Months passed; and during all
those months I pondered the mystery of the Professor's fate, and the
fate of his machines. But my fevered brain could offer no solution
until I read of what was happening in Arizona; then, then...."

Milton Baxter leaned forward, his voice broke.

"Then," he cried, "then I understood! Professor Reubens had succeeded
in his last experiment. He had opened the door to earth for the bird
intelligences from the atom and they had come through and sl