"That will do very well," he said. "It will be safe if any one else should find it. Seeker knows where to come to."

McMurtrie put the note in an envelope which he placed in the centre of the table.

"And now," he said, pushing back his chair, "the sooner we are out of this the better."

I felt that if I was going to interfere the right time had now arrived. Von Brunig's reply to Savaroff had given me just the opening I needed.

"One moment, gentlemen!" I said, getting up from the couch.

They all three turned in obvious surprise at the interruption.

"Well?" rapped out von Brunig, "what is it?"

"I was under the impression," I said, "that this new explosive of mine was to be put on the market as an ordinary commercial enterprise."

McMurtrie rose from his chair and took a step forward.

"You are perfectly right," he said. "Why should you think otherwise?"

"In that case," I replied steadily, "I should like to know what Mr.

von Brunig meant by his remark about the 'future of Germany.'"

There was a short pause.

"Ach, Himmel!" broke out von Brunig. "What does it matter? What are we wasting time for? Tell him if he wishes."

"Why, certainly," said McMurtrie, smiling. "There is no mystery about it. I was merely keeping the matter quiet until it was settled." He turned to me. "The German Government have made us a very good offer for your invention, provided of course that it will do what you claim."

"It will do what I claim all right," I said coolly, "but I don't wish to sell it to the German Government."

There was a sort of explosive gasp from von Brunig and Savaroff, and I saw McMurtrie's eyes narrow into two dangerous cat-like slits.

"_You don't-wish!_" he repeated icily. "May I ask why?"

"Certainly," I said. "With the sole command of an explosive as powerful as mine, Germany would be in a position to smash England in about six weeks."

"And suppose she was," interrupted von Brunig. "What in G.o.d's name does it matter to you--an escaped convict?"

His voice rang with impatience and contempt, and I felt my own temper rising.

"It matters just sufficiently," I said, "that I'll see you in h.e.l.l first."

McMurtrie came slowly up to me, and looked me straight in the eyes.

His face was white and terrible--a livid mask of controlled anger.

"You fool," he said almost pityingly. "You incredible fool! Do you imagine that you have any choice in the matter?"

Von Brunig and Savaroff moved up alongside of him, and I stood there confronting the three of them.

"You have heard my choice," I said.

McMurtrie laughed. It was precisely the way in which I should imagine the devil laughs on the rare occasions when he is still amused.

"You are evidently a bad judge of character, Mr. Lyndon," he said.

"People who attempt to break faith with me are apt to find it a very unhealthy occupation."

I felt utterly reckless now. I had done my best to delay things, and if neither the police nor the Secret Service was ready to take advantage of it, so much the worse for them--and me.

"I can quite believe you, doctor," I said pleasantly. "I should imagine you were a dangerous ruffian from the intelligent way in which you murdered Marks."

It was a last desperate stroke, but it went home with startling effect.

Savaroff's face flushed purple, and with a fierce oath he gripped the back of a chair and swung it up over his head. The doctor stopped him with a gesture of his hand. As for von Brunig, he stood where he was, staring from one to the other of us in angry bewilderment. He evidently hadn't the remotest notion what I was talking about.

McMurtrie was the first to speak. "Yes," he said, in his coolest, silkiest voice. "I did kill Marks. He was the last person who betrayed me. I rather think you will envy him before I have finished with you, Mr. Lyndon."

"A thousand devils!" cried von Brunig furiously: "what does all this nonsense mean? We may have the police here any moment. Knock him on the head, the fool, and--"

"Stop!"

The single word cut in with startling clearness. We all spun round in the direction of the sound, and there, standing in the window just between the two curtains, was the solitary figure of Mr. Bruce Latimer. He was accompanied by a Mauser pistol which flickered thoughtfully over the four of us.

"Keep still," he drawled--"quite still, please. I shall shoot the first man who moves."

There was a moment of rather trenchant silence. Then von Brunig moistened his lips with his tongue.

"Are you mad, sir?" he began hoa.r.s.ely. "By what--"

With a lightning-like movement McMurtrie slipped his right hand into his side pocket, and as he did so Latimer instantly levelled his pistol. The two shots rang out simultaneously, but except for a cry and a crash of broken gla.s.s I knew nothing of what had happened. In one stride I had flung myself on Savaroff, and just as he drew his revolver I let him have it fair and square on the jaw. Dropping his weapon, he reeled backwards into von Brunig, and the pair of them went to the floor with a thud that shook the building. Almost at the same moment both the door and the window burst violently open, and two men came charging into the room.

The first of the intruders was Tommy Morrison. I recognized him just as I was making an instinctive dive for Savaroff's revolver, under the unpleasant impression that Hoffman and the other German had returned from the post-office. You can imagine the delight with which I scrambled up again, clutching that useful if rather belated weapon in my hand.

One glance round showed me everything there was to see.

Face downwards in a little pool of blood lay the motionless figure of McMurtrie. Savaroff also was still--his huge bulk sprawled in fantastic helplessness across the floor. Only von Brunig had moved; he was sitting up on his hands, staring in a half-dazed fashion down the barrel of Latimer's Mauser.

It was Latimer himself who renewed the conversation.

"Come and fix up these two, Ellis," he said. "I will see to the other."

The man who had burst in with Tommy, a lithe, hard-looking fellow in a blue suit, walked crisply across the room, and pulling out a pair of light hand-cuffs snapped them round von Brunig's wrists. He then performed a similar service for the still unconscious Savaroff.

The next moment Latimer, Tommy, and I were kneeling round the prostrate figure of the doctor. We lifted him up very gently and turned him over on to his back, using a rolled-up rug as a pillow for his head. He had been shot through the right lung and was bleeding at the mouth.

Latimer bent over and made a brief examination of the wound. Then with a slight shake of his head he knelt back.

"I'm afraid there's no hope," he remarked dispa.s.sionately. "It's a pity. We might have got some useful information out of him."

There was a short pause, and then quite suddenly the dying man opened his eyes. It may have been fancy, but it seemed to me that for a moment a shadow of the old mocking smile flitted across his face. His lips moved, faintly, as though he were trying to speak. I bent down to listen, but even as I did so there came a fresh rush of blood into his throat, and with a long shudder that strange sinister spirit of his pa.s.sed over into the darkness. I shall always wonder what it was that he left unsaid.