"A Miss Mary Carson," she lisped in soft English.

"Let the lady enter," waved Long Sin, with a smile of subtle satisfaction.

The girl bowed again and silently left the room, returning with a handsome, very well dressed white woman.

It would be difficult to a.n.a.lyze just what the fascination was that Long Sin exercised over Mary Carson. But as the servant left the room, Mary bowed almost as deferentially as the little Chinese girl. Long merely nodded in reply.

After a moment, he slowly rose and took from a drawer a newspaper clipping. Without a word, he handed it to Mary. She looked at it with interest, as one woman always does at the picture of another pretty woman. It was a newspaper cut of Elaine, under which was:

ELAINE DODGE, THE HEIRESS, WHOSE BATTLE WITH THE CLUTCHING HAND IS CREATING WORLD WIDE INTEREST.

"Now," he began, at last, breaking the silence, "I'll show you just what I want you to do."

He went over to the wall and took down a curious long Chinese knife from a scabbard which hung there conspicuously.

"See that?" he added, holding it up.

Before she could say a word, he had plunged the knife, apparently, into his own breast.

"Oh!" cried Mary, startled.

She expected to see him fall. But nothing happened. Long Sin laughed.

It was an Oriental trick knife in which the blade telescoped into the handle.

"Look at it," he added, handing it to her.

Long Sin took a bladder of water from a table nearby and concealed it under his coat. "Now, you stab me," he directed.

Mary hesitated. But he repeated the command and she plunged the knife gingerly at him. It telescoped. He made her try it over and she stabbed more resolutely. The water from the bladder poured out.

"Good!" cried Long Sin, much pleased. "Now," he added, seating himself beside her, "I want you to lure Elaine here."

Mary looked at him inquiringly as he returned the knife to its scabbard on the wall. "Remember where it is," he continued. "Now, if you will come into the other room I will show you how to get her."

I had been amusing myself by rigging up a contrivance by which I could make it possible to see through or rather over, a door. The idea had been suggested to me by the cystoscope which physicians use in order to look down one's throat, and I had calculated that by using three mirrors placed at proper angles, I could easily reflect rays down to the level of my eye.

Kennedy, who had been busy in the other end of the laboratory, happened to look over in my direction. "What's the big idea, Walter?" he asked.

It was, I admit, a rather c.u.mbersome and clumsy affair.

"Well, you see, Craig," I explained, "you put the top mirror through the transom of a door and--"

Kennedy interrupted with a hearty burst of laughter. "But suppose the door has no transom?" he asked, pointing to our own door.

I scratched my head, thoughtfully. I had a.s.sumed that the door would have a transom. A moment later, Craig went to the cabinet and drew out a tube about as big around as a putty blower and as long.

"Now, here's what I call my detectascope," he remarked. "None of your mirrors for me."

"I know," I said somewhat nettled, "but what can you see through that putty blower? A key hole is just as good."

"Do you realize how little you can really see through a key hole?" he replied confidently. "Try it over there."

I did and to tell the truth I could see merely a little part of the hall. Then Kennedy inserted the detectascope.

"Look through that," he directed.

I put my eye to the eye-piece and gazed through the bulging lens of the other end. I could see almost the whole hall.

"That," he explained, "is what is known as a fish-eye lens--a lens that looks through an angle of some 180 degrees, almost twice that of the widest angle lens I know of."

I said nothing, but tossed my own crude invention into the corner, while Craig went back to work.

Elaine was playing with "Rusty" when Jennings brought in a card on which was engraved the name, "Miss Mary Carson," and underneath, in pencil, was written "Belgian Relief Committee."

"How interesting," commented Elaine, rising and accompanying Jennings back into the drawing room. "I wonder what she wants. Very pleased to meet you, Miss Carson," she greeted her visitor.

"You see, Miss Dodge," began Mary, "we're getting up this movement to help the Belgians and we have splendid backing. Just let me show you some of the names on our committee."

She handed Elaine a list which read:

BELGIAN RELIEF COMMITTEE

Mrs. Warburton Fish Mrs. Hamilton Beekman Mrs. C. August Iselm Mrs. Belmont Rivington Mrs. Rupert Solvay.

"I've just been sent to see if I cannot persuade you to join the committee and attend a meeting at Mrs. Rivington's," she went on.

"Why, er," considered Elaine thoughtfully, "er--yes. It must be all right with such people in it."

"Can you go with me now?"

"Just as well as later," agreed Elaine.

They went out together, and, as they were leaving the house a man who had been loitering outside looked at Elaine, then fixedly at her companion.

No sooner had they gone than he sped off to a car waiting around the corner. In the dark depths was a sinister figure, the master criminal himself. The watcher had been an emissary of the Clutching Hand.

"Chief," he whispered eagerly, "You know Adventuress Mary? Well, she's got Elaine Dodge in tow!"

"The deuce!" cried Clutching Hand. "Then we must teach Mary Carson, or whoever she is working for, a lesson. No one shall interfere with our affairs. Follow them!"

Elaine and Mary had gone downtown, talking animatedly, and walked down the avenue toward Mrs. Rivington's apartment.

Meanwhile, Long Sin, still in his Chinese costume, was explaining to the servant just what he wished done, pointing out the dagger on the wall and replacing the bladder under his jacket. A box of opium was on the table, and he was giving most explicit directions. It was into such a web that Elaine was being unwittingly led by Mary.

Entering the hallway of the apartment, Mary rang the bell.

Long heard it. "Answer it," he directed the servant who hastened to do so, while Long glided like a serpent into a back room.

The servant opened the door and Elaine and Mary entered. He closed the door and almost before they knew locked it and was gone into the back room.