The five now conferred a bit and it was agreed that this time the inquisitive Mr. Locke would surely trouble them no more.

“With Locke out of the way,” promised Paul to Dora, “the road to our fortune is clear.”

A moment later Paul left the apartment, descended in the elevator, and jumped into a taxicab and was off.

Locke from his cab had, of course, seen all this, had seen Paul and Dora on the balcony and the departure.  But he knew nothing of the three men who had gone to the same apartment.

He waited until Paul passed out of sight, then stepped out of his cab, making a careful calculation as to the exact location of the woman’s apartment, for he had determined to find out about her.  From the hall boy he learned that it was De Luxe Dora, of whom he knew, and it was only a matter of seconds when he was admitted.

Dora swept over graciously toward him.

“Will you answer me one question?” he asked, in answer to a query from her.

She nodded assent.

“How long have you known Mr. Balcom’s son?”

“He is an old friend,” she replied.  “I’m expecting him to return 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.