ing in fright, clutching
the pistol in her hand, trying to catch the sounds of men in that
chamber of horror.

She heard, then, a faint whimpering, and then noises which she
identified in her mind as something being dragged along the marble
flooring. A muffled scream, weak, reached her ears, and as she took a
step forward, silence came.

She listened longer, but now the sunlight coming through the window to
make murky patches in the opaque black fog was her chief sensation.

"Walter!" she called.

"Go back, Betty, go back!"

The mist seemed to muffle voices as well as obscure the vision. She
advanced farther into the laboratory, trying to locate Marable. Bravely
the girl pushed toward the biggest amber block. It was here that she
felt instinctively that she would find the source of danger.

"Leffler!" she heard Marable say, almost at her elbow, and the young man
groaned. The girl came upon him, bending over something on the floor.

* * * * *

She knelt beside him, gripping his arm. Now she could see the outline of
Leffler's body at her feet. The wealthy collector was doubled up on the
ground, shrivelled as had been Rooney. His feet, moving as though by
reflex action, patted the floor from time to time, making a curious
clicking sound as the buttons of his gray spats struck the marble.

But it was obvious, even in the murky light, that Leffler was dead, that
he had been sucked dry of blood.

Betty Young screamed. She could not help it. The black fog choked her
and she gasped for breath. Leaving Marable, she ran toward the windows
to throw them open.

The first one she tried was heavy, and she smashed the glass with the
butt of the gun. She broke several panes in two of the windows, and the
mist rolled out from the laboratory.

She started to return to the side of Marable. He uttered a sudden shout,
and she hurried back to where she had left him, stumbling over Leffler's
body, recoiling at this touch of death.

Marable was not there, but she could hear him nearby.

Cool air was rushing in from the windows, and gradually the fog was
disappearing. Betty Young saw Marable now, standing nearby, staring at
the bulk of an amber block which was still covered by its canvas shroud.
Though not as large as the prize exhibit, this block of amber was large
and filled many yards of space.

"Betty, please go outside and call some of the men," begged Marable.

But he did not look at her,