s at his heels. "Please get yourself a
gun," she said, clutching his arm and holding him back.

"All right. I'll borrow one from a guard."

He returned to the front doors, and came back, slipping a large pistol
into his side pocket.

"I want you to wait here," he said.

"No. I'm going with you."

"Please," he said. "As your superior, I order you to remain downstairs."

The girl shrugged. She allowed him to climb the stairs to the first
floor, and then she hurried back in search of Smythe.

* * * * *

Smythe obtained a gun for her, and as she did not wish to wait for the
slow elevator, she ran up the steps. Smythe could not tell her
definitely what had occurred in the upper laboratory that had caused the
museum to be closed for the day.

Her heart beating swiftly, Betty Young hurried up the second flight of
stairs to the third floor. A workman, whom the girl recognized as a
manual laborer in the paleontological rooms, came running down, passing
her in full flight, a look of abject terror on his face.

"What is it?" she cried.

He was so frightened he could not talk logically. "There was a black
fog--I saw a red snake with legs--"

She waited for no more. A pang of fear for the safety of Marable shot
through her heart, and she forced herself on to the top floor.

Up there was a haze, faintly black, which filled the corridors. As Betty
Young drew closer to the door of the paleontological laboratories, the
mist grew more opaque. It was as though a sooty fog permeated the air,
and the girl could see it was pouring from the door of the laboratory in
heavy coils. And her nostrils caught the strange odor of fetid musk.

She was greatly frightened; but she gripped the gun and pushed on.

* * * * *

Then to her ears came the sound of a scream, the terrible scream of a
mortally wounded man. Instinctively she knew it was not Marable, but she
feared for the young professor, and with an answering cry she rushed
into the smoky atmosphere of the outer laboratories.

"Walter!" she called.

But evidently he did not hear her, for no reply came. Or was it that
something had happened to him?

She paused on the threshold of the big room where were the amber blocks.

About the vast floor space stood the numerous masses of stone and amber,
some covered with immense canvas shrouds which made them look like ghost
hillocks in the dimness. Betty Young stood, gasp