e floor, radiating from the
sepia.

"Doctor Marable," she said, "please don't--don't look any longer. Leave
this terrible place for the day, anyway, until we see what happens in
the next twenty-four hours."

He smiled and shook his head. "I must make a search," he replied. "My
brain calls me a fool, but just the same, I'm worried."

"Do you really think ...?"

He nodded, divining her thought. The girl shivered. She felt terror
mounting to her heart, and the matter-of-fact attitudes of the others in
the great laboratory did not allay her fears.

Rooney's body was removed. The place was cleaned up by workmen, and
Marable's search--if that was what his constant roving about the
laboratory could be called--ceased for a time. The chemist's report came
in. The black liquid was some sort of animal secretion, melonotic
probably.

* * * * *

In spite of the fact that they had learned so many facts about the
murder, they as yet had not solved the mystery. Who had murdered Rooney,
and why? And where had his blood gone to? In no other rooms could be
found any traces of a struggle.

"If you won't do anything else, please carry a gun," begged Betty of
Marable. "I'm going to try to take father home, right after lunch, if
he'll go. He's so stubborn. I can't make him take care. I've got to
watch him and stay beside him."

"Very well," replied Marable. "I'll get a revolver. Not that I think it
would be of much use, if I did find--" He broke off, and shrugged his
broad shoulders.

Leffler came storming into the room. "What's this I hear?" he cried,
approaching Marable. "A watchman killed in the night? Carelessness, man,
carelessness! The authorities here are absurd! They hold priceless
treasures and allow thieves to enter and wreak their will. You, Marable,
what's all this mean?"

Leffler was angry. Marable looked into his red face coolly. "We do the
best we can, Mr. Leffler," he said. "It is unlikely that anyone would
wish to steal such a thing as that block of amber."

He waved toward the giant mass.

Leffler made a gesture of impatience. "It cost me many thousands of
dollars," he cried.

"It is time for lunch, Professor," said Betty.

Marable bowed to Leffler and left the millionaire sputtering away,
inspecting the various specimens he had contributed.

The one o'clock gong had struck, and all the workers and investigators
were leaving in paleontological laboratories for a bite to ea