n the ceiling
through which it came, this beam was in diameter not more than two
inches, but as it extended downward, it widened, taking the form of a
long, thin, truncated cone, so that its width, where it impinged upon
his face, was perhaps equal to twice that of a man's hand.

The darkness of the room about him made the beam of light seem a
tangible, material thing. Its brilliance was unwavering--it extended
from the ceiling to the surface of his face with the solidity, almost,
of some huge, glittering icicle. He felt as though, were his hands but
free, he could brush it aside, fling it off bodily into the darkness.

The effort of looking directly at the source of the light made his eyes
smart with pain, but he found that by half-closing them, he could look
off into the darkness, through the brilliant cone. In the pathway of its
rays danced and tumbled innumerable dust specks--he knew then but for
their presence, to afford the light a reflecting surface, its rays would
be invisible to him.

In color the light was not yellow, like sunlight, but had a cold
violet-blue quality, more nearly resembling moonlight. Its intensity, as
well as the shape of the light cone, made him conclude that it was being
focused through a powerful lens, or projected by means of a brilliant
reflector.

He could imagine no possible reason for the situation in which he found
himself. What the purpose of the beam of light was; why it thus focused
upon his upturned face, he could not guess. He thought about it for many
minutes, his eyes closed, his head straining restlessly toward the soft
outer darkness. Presently there flashed into his mind Dr. Hartmann's
words at their last meeting: "While I know how to cure mental disorders,
I also know how to create them." The thought made him shudder. Was this,
then, the explanation of his predicament? Somewhere he had read, not
long before, a newspaper account of the investigations of certain
Italian scientists, concerning the effect of the violet and ultra-violet
light rays upon the cells of the brain. He could not recollect just what
the conclusions had been, but he did remember that the newspaper article
spoke of the popular superstition that moonlight could cause insanity.
He knew Hartmann to be a scientist of vast ability and resource, and
realized that back of the elaborate preparations he had evidently made
must lie some sinister purpose.

For what seemed an eternity he lay thinking, unable to