"Well, gentlemen? What is it?"

"I should like a word with Dr. Michael Strange," said my companion quietly.

"I am Michael Strange."

"And I," replied Hartnett, with a suggestion of a smile, "am Raoul Hartnett, from Scotland Yard."

I did not see any sign of emotion on Strange's face. He stepped back in silence to allow us to enter. Then closing the big door after us, he led the way along a carpeted hall to a small, ill-lighted room just beyond.

Here he motioned us to be seated, he himself standing upright beside the table, facing us.

"From Scotland Yard," he said, and the tone was heavy with dull sarcasm.

"I am at your service, Mr. Hartnett."

And now, for the first time, I wondered just why Drake had insisted on my coming here to this gloomy house in Mate Lane. Why he had so deliberately arranged a subst.i.tute so that Michael Strange should not come face to face with him directly. Evidently Hartnett had been carefully instructed as to his course of action--but why this seemingly unnecessary caution on Drake's part? And now, after we had gained admission, what excuse would Hartnett offer for the intrusion? Surely he would not follow the bull-headed role of a common policeman!

There was no anger, no attempt at dramatics, in Hartnett's voice. He looked quietly up at our host.

"Dr. Strange," he said at length, "I have come to you for your a.s.sistance. Last night, some time after midnight, Franklin White was strangled to death. He was murdered, according to substantial evidence, by the girl he was going to marry--Margot Vernee. I come to you because you know this girl rather well, and can perhaps help Scotland Yard in finding her motive for killing White."

Michael Strange said nothing. He stood there, scowling down at my companion in silence. And I, too, I must admit, turned upon Hartnett with a stare of bewilderment. His accusation of Margot had brought a sense of horror to me. I had expected almost anything from him, even to a mad accusation of Strange himself. But I had hardly foreseen this cold blooded declaration.

"You understand, Doctor," Hartnett went on, in that same ironical drawl, "that we do not believe Margot Vernee did this thing herself. She had a companion, undoubtedly, one who accompanied her to the house on After Street, and a.s.sisted her in the crime. Who that companion was, we are not sure; but there is decidedly a case of suspicion against a certain young London sportsman. This fellow is known to have prowled about the White mansion both on the night of the murder and the night before."

Hartnett glanced up casually. Strange's face was a total mask. When he nodded, the nod was the most even and mechanical thing I have ever seen.

Certainly this man could control his emotions!

"Naturally, Doctor," Hartnett said, "we have gone rather deeply into the past life of the lady in question. Your name appears, of course, in a rather unimportant interval when Margot Vernee resided in Paris. And so we come to you in the hope that you can perhaps give us some slight bit of information--something that seems insignificant, perhaps, to you, but which may put us on the right track."

It was a careful speech. Even as Hartnett spoke it, I could have sworn that the words were Drake's, and had been memorized. But Michael Strange merely stepped back to the table and faced us without a word. He was probably, during that brief interlude, attempting to realize his position, and to discover just how much Raoul Hartnett actually knew.

And then, after his interim of silence, he came forward sullenly and stood over my comrade.

"I will tell you this much, Mr. Hartnett of Scotland Yard," he said bitterly: "My relations with Margot Vernee are not an open book to be pa.s.sed through the clumsy fingers of ignorant police officers. As to this murder, I know nothing. At the time of it, I was seated in this room in company with a distinguished group of scientific friends. I will tell you, on authority, that Margot _did not murder her lover_. Why?

Because she loved him!"

The last words were heavy with bitterness. Before they had died into silence, Michael Strange had opened the door of his study.

"If you please, gentlemen," he said quietly.

Hartnett got to his feet. For an instant he stood facing the gorilla-like form of our host; then he stepped over the sill, without a word. We pa.s.sed down the unlighted corridor in silence, while Strange stood in the door of his study, watching us. I could not help but feel, as we left that gloomy house, that Strange had suddenly focused his entire attention upon me, and had ignored my companion. I could feel those eyes upon me, and feel the force of the will behind them. A decided feeling of uneasiness crept over me, and I shuddered.

A moment later the big outer door had closed shut after us, and we were alone in Mate Lane. Alone, that is, until a third figure joined us in the shadows, and Drake's hand closed over my arm.

"Capital, Dale," he said triumphantly. "For half an hour you entertained him, you and Hartnett. And for half an hour I've had the unlimited freedom of his inner rooms, with the aid of an unlocked window on the lower floor. Those inner rooms, gentlemen, are significant--very!"

As we walked the length of Mate Lane, the gaunt, sinister home of Michael Strange became an indistinct outline in the pitch behind us.

Drake said nothing more on the return trip, until we had nearly reached my rooms. Then he turned to me with a smile.

"We are one up on our friend, Dale," he said. "He does not know, just now, which is the bigger fool--you or Hartnett here. However, I imagine Hartnett will be the victim of some very unusual events before many hours have pa.s.sed!"

That was all. At least, all of significance. I left the two Scotland Yard men at the opening of Cheney Lane, and continued alone to my rooms.

I opened the door and let myself in quietly. And there some few hours later, began the last and most horrible phase of the case of the murder machine.

It begin--or to be more accurate, I began to react to it--at three o'clock in the morning. I was alone, and the rooms were dark. For hours I had sat quietly by the table, considering the significant events of the past few days. Sleep was impossible with so many unanswered questions staring into me, and so I sat there wondering.

Did Drake actually believe that Margot Vernee's simple story had been a ruse--that she had in truth killed her lover on that midnight intrusion of his home? Did he believe that Michael Strange knew of that intrusion--that he had possibly planned it himself, and aided her, in order that Margot might be free to return to him? Did Strange know of that other intrusion, and of the uncanny power which had driven Sir John Harmon, and supposedly driven Margot to that house on After Street?

Those were the questions that still remained without answers: and it was over those questions that I pondered, while my surroundings became darker and more silent as the hour became more advanced. I heard the clock strike three, and heard the answering drone of Big Ben from the square.

And then it began. At first it was little more than a sense of nervousness. Before I had been content to sit in my chair and doze. Now, in spite of myself, I found myself pacing the floor, back and forth like a caged animal. I could have sworn, at the time, that some sinister presence had found entrance to my room. Yet the room was empty. And I could have sworn, too, that some silent power of will was commanding me, with undeniable force, to go out--out into the darkness of Cheney Lane.

I fought it bitterly. I laughed at it, yet even through my laugh came the memory of Sir John Harmon and Margot, and what they had told me. And then, unable to resist that unspoken demand, I seized my hat and coat and went out.

Cheney Lane was deserted, utterly still. At the end of it, the street lamp glowed dully, throwing a patch of ghastly light over the side of the adjoining building. I hurried through the shadows, and as I walked, a single idea had possession of me. I must hurry, I thought, with all possible speed, to that grim house in Mate Lane--number seven.

Where that deliberate desire came from I did not know. I did not stop to reason. Something had commanded me to go at once to Michael Strange's home. And though I stopped more than once, deliberately turning in my tracks, inevitably I was forced to retrace my steps and continue.

I remember pa.s.sing through the square, and prowling through the unlightened side streets that lay beyond. Three miles separated Cheney Lane from Mate Lane, and I had been over the route only once before, in a cab. Yet I followed that route without a single false turn, followed it instinctively. At every intersecting street I was dragged in a certain direction and not once was I allowed to hesitate. It was as though some unseen demon perched on my shoulders, as the demon of the sea rode Sinbad, and pointed out the way.

Only one disturbing thing occurred on that night journey through London.

I had turned into a narrow street hardly more than a quarter mile from my destination; and before me, in the shadows, I made out the form of a shuffling old man. And here, as I watched him, I was conscious of a new, mad desire. I crept upon him stealthily, without a sound. My hands were outstretched, clutching, for his throat. At that moment I should have killed him!

I cannot explain it. During that brief interval I was a murderer at heart. I wanted to kill. And now that I remember it, the desire had been pregnant in me ever since the lights of Cheney Lane had died behind me.

All the time that I prowled through those black streets, murder lurked in my heart. I should have killed the first man who crossed my path.

But I did not kill him. Thank G.o.d, as my fingers twisted toward the back of his throat, that mad desire suddenly left me. I stood still, while the old fellow, still unsuspecting, shuffled, away into the darkness.

Then, dropping my hands with a sob of helplessness, I went forward again.

And so I reached Mate Lane, and the huge gray house that awaited me.

This time, as I mounted the stone steps, the old house seemed even more repulsive and horrible. I dreaded to see that door open, but I could not retreat.

I dropped the knocker heavily. A moment pa.s.sed: and then, precisely as before, the huge door swung inward. Michael Strange stood before me.

He did not speak. Perhaps, if he had spoken, that fiendish spell would have been broken, and I should have returned, even then, to my own peaceful little rooms in Cheney Lane. No--he merely held the door for me to enter, and as I pa.s.sed him he stood there, watching me with a significant smile.