Cat-like, he advanced, but instead of striking at them, he quietly took a seat in a chair close behind them, a magazine revolver in his hand.

They turned at a slight noise and saw him. Genuine fright was now on their faces as they looked at him, open mouthed.

"What's all this?" he growled. "I am known as the Clutching Hand. I allow no interferences with my affairs. Tell me what you are doing here with Elaine Dodge."

Their beady almond eyes flashed fear. Clutching Hand moved menacingly.

There was nothing for the astute Long Sin to do but to submit. Cowed by the well-known power of the master criminal, he took Clutching Hand into his confidence.

With a low bow, Long Sin spread out his hands in surrender and submission.

"I will tell you, honorable sir," he said at length.

"Go on!" growled the criminal.

Quickly Long rehea.r.s.ed what had happened, from the moment the idea of blackmail had entered his head.

"How about Mary Carson?" asked Clutching Hand. "I saw her here."

Long gave a glance of almost superst.i.tious dread at the man, as if he had an evil eye.

"She will be back--is here now," he added, opening the door at a knock and admitting her.

Adventuress Mary had hurried back to see that all was right. This time Mary was genuinely scared at the forbidding figure of which she had heard.

"It is all right," pacified Long. "Henceforth we work with the honorable Clutching Hand."

Clutching Hand continued to emphasize his demands on them, punctuating his sentences by flourishes of the gun as he gave them the signs and pa.s.swords which would enable them to work with his own emissaries.

It was a strange initiation.

At home at last, Elaine sank down into a deep library chair and stared straight ahead. She saw visions of arrest and trial, of the terrible electric chair with herself in it, bound, and of the giving of the fatal signal for turning on the current.

Were such things as these going to happen to her, without Kennedy's help? Why had they quarreled? She buried her face in her hands and wept.

Then she could stand it no longer. She had not taken off her street clothes. She rose and almost fled from the house.

Kennedy and I were still in the laboratory when a knock sounded at the door. I went to the door and opened it. There stood Elaine Dodge.

It was a complete surprise to Craig. There was silence between them for a moment and they merely looked at each other. Elaine was pale and woebegone.

At last Kennedy took a quick step toward her and led her to a chair.

Still he felt a sort of constraint.

"What IS the matter?" he asked at length.

She hesitated, then suddenly burst out, "Craig--I--I am--a murderess!"

I have never seen such a look on Craig's face. I know he wanted to laugh and say, "YOU--a murderess?" yet he would not have offended even her self accusation for the world. He managed to do the right thing and say nothing.

Then she poured forth the story substantially as I have set it down, but without the explanation which at that time was not known to any of us.

"Oh," expostulated Craig, "there must be some mistake. It's impossible--impossible."

"No," she a.s.serted. "Look--here's my handkerchief all spotted with blood."

She opened the bag and displayed the blood-spotted handkerchief. He took it and examined it carefully.

"Elaine," he said earnestly, not at all displeased, I could see that something had come up that might blot out the past unfortunate misunderstanding, "there simply must be something wrong here. Leave this handkerchief with me. I'll do my best."

There was still a little restraint between them. She was almost ready to beg his pardon, for all the coolness there had been between them, yet still hesitated.

"Thank you," she said simply as she left the laboratory.

Craig went to work abruptly without a word. On the laboratory table he placed his splendid microscope and several cases of slides as well as innumerable micro-photographs. He had been working for some time when he looked up.

"Ever hear of Dr. Edward Reichert of the University of Pennsylvania and his wonderful discoveries of how blood crystals vary in different species?" he asked.

I had not, but did not admit it.

"Well," he went on, "there is a blood test so delicate that one might almost say that he could identify a criminal by the finger prints, so to speak, of his blood crystals. The hemoglobin or red coloring matter forms crystals and the variations of these crystals both in form and molecular construction are such that they set apart every species of animal from every other, and even the races of men--perhaps may even set apart individuals. Here, Walter, we have sample of human blood crystals."

I looked through the microscope as he directed. There I could see the crystals sharply defined.

"And here," he added, "are the crystals of the blood on Elaine's handkerchief."

I looked again as he changed the slides. There was a marked difference and I looked up at him quickly.

"It is dog's blood--not human blood," he said simply.

I looked again at the two sets of slides. There could be no doubt that there was a plain difference.

"Wonderful!" I exclaimed.

"Yes--wonderful," he agreed, "but what's the game back of all this--that's the main question now."

Long after Clutching Hand had left, Long Sin was giving instructions to his servant and Adventuress Mary just how he had had to change his plans as a result of the unexpected visit.

"Very well," nodded Mary as she left him, "I will do as you say--trust me."

It was not much later, then, that Elaine received a second visit from Mary.

"Show her in, Jennings," she said to the butler nervously.

Indeed, she felt that every eye must be upon her. Even Jennings would know of her guilt soon.

Anxiously, therefore, Elaine looked at her visitor.

"Do you know why the servant allowed us to leave the apartment?"

whispered Mary with a glance about fearfully, as if the walls had ears.