turn at any
moment. Won't you be seated? Please excuse me just a moment."

Before Locke could say a word she had left the room. Left alone himself,
Locke took in all the details of the room and again and again his eye
wandered to a Louis XIV desk.

Feeling certain that this woman was without doubt connected in some way
with the plots, he felt justified in opening the desk to obtain
evidence. He tiptoed over to it and tried to open it. It stuck at first,
but after one or two silent, well-directed blows which he so well knew
how to administer the sliding panel stood unlocked.

He glanced around. There was no one to be seen. He moved back the panel.
There was a flash and a tiny puff of smoke. Locke coughed once, clutched
at his throat, and lay gasping on the floor.

Immediately the three men rushed out, carrying ropes and holding
handkerchiefs to their nostrils. One ran to the window and threw it wide
open, admitting gusts of air to clear away the fumes. The others began
to bind Locke as De Luxe Dora appeared in the doorway and calmly
directed operations.

On the roof of the apartment several moments later in the just-gathering
dusk five figures might have been seen. Three men and a woman were
conferring, while at their feet was a man tightly bound and unconscious.

In the background was a huge water-tank, with a ladder leading to its
brim.

Suddenly the conspirators straightened up. They had come to a decision.
The three men lifted the unconscious figure and bore it up the ladder.
The tank was empty. One of the men jumped down into it, while the others
lowered their victim after him. Then they passed down ropes.

There were two spouts at the bottom of the tank through which water was
pumped. Also there were pipes running upward. To these pipes they tied
Locke. Then the men climbed out and, as their last fiendish act, turned
the water on.

With a sneer Dora turned and led the way down-stairs again.

"They'll find his body when they have to clean the tank again," she
exclaimed.

At Brent Rock, during the absence of Locke, Eva had donned her street
clothes, since it was nearing the hour of eight when she and Locke were
due to be at the inventor's workshop to render the restitution. She went
down-stairs and asked the butler about Locke. But the man replied that
Mr. Locke had not yet returned.

Eva was very uneasy by this time, and, thinking to save time, was about
to go down to the Graveyard of Genius to get th