Barmouth could see a little speck of foam like a white feather on the lips of his companion. He saw Anstruther throw up his head, and the apple of his throat moved as if in the act of swallowing. The whole thing had been so swift and unexpected, that Barmouth could not blame himself for what had happened. There was no occasion to tell him that the pearl had contained some deadly poison, for already the effect of it was apparent on Anstruther's features. He gasped painfully as if some terrible pain had gripped him by the heart, his features twitched horribly, yet he smiled with the air of a man who is by no means displeased with himself.

"Yes," he said quite naturally, "I think it will be just as well if you called in the warder who is watching us through that grating in the door, and tell him everything that has happened."

Barmouth lost no time in doing so. There was a great tramping and commotion in the corridor outside, and presently Bates and the prison doctor rushed in. By this time Anstruther was seated on the only chair in the cell; there was a heavy bead of moisture on his face. He smiled faintly at Bates.

"It is exactly as Lord Barmouth has said," he explained. "When your people deprived me of everything that I possessed they forgot to remove a tiny pearl-headed pin from my scarf. It was only a very small pearl--you could have bought the thing in any West-End shop for a sovereign; but the gem was not so innocent as it appeared to be. Inside I had caused to be placed one spot of deadly poison no larger than a pin's head. I have had it there for years in case of an emergency. I have always had a presentiment that sooner or later the end would be thus, and I am much too active-minded a man to dare to pass years in jail. I should have gone mad under treatment like that. Therefore, you see I was quite ready for you. I had only to take that pin from my tie, and make the tiniest puncture in the tip of my tongue, then all I had to do was to crush the pearl within my teeth, and the thing was done. There need be no inquest; the poison in question was one spot from the fang of a cobra. See, the end is very near."

Anstruther staggered to his feet, threw his hands above his head, and collapsed in a heap on the floor. There was one fearful shuddering contortion of the muscles, and after that a rigid stillness. The prison doctor bent down, and examined the silent form carefully. He shook his head gravely.

"My services here are absolutely useless," he said. "The man is dead. I only wonder that he lived so long. It was a sad ending to what might have been a brilliant career."

"It was a brilliant career," Bates muttered. "We never had a detective in the Force as clever as Mr. Anstruther. Shall I call a cab for you, my lord? There is nothing to gain by your waiting any longer."

Barmouth nodded in an abstracted kind of way; he hardly appeared to heed what Bates was saying. In the same dreamy fashion he was driven homewards. On reaching Belgrave Square he found that Benin had gone off on some business, leaving Jack and Rigby behind him. In a few words he told the others what had happened. There was nothing more to be said on the matter, and no great feeling was expressed, seeing that Anstruther had never been anything else but an enemy to all of them.

"He seemed desirous of making amends at the last," Barmouth said. "For instance, he has shown us a way whereby my wife's unfortunate sister can be forever free of Padini. Also he informed me that Miss Claire Helmsley's fortune is absolutely intact. He was cynical to the last, and suggested that Jack here should marry the lady of his choice without delay."

"That is very good of him," Jack said drily. "But as far as I am concerned, I shall not be in the least sorry to hear that Claire has nothing. I do not want the suggestion made that I am in any way a fortune hunter. It is not a pleasant idea."

"What is the good of talking that nonsense," Rigby exclaimed. "My dear fellow, you are getting on splendidly with your literary work, and in a year or so from now your income will be quite equal to Miss Helmsley's. Besides, nobody who knew you would think of accusing you of fortune hunting. And so long as Miss Helmsley shares the opinions of your friends, I don't see that it in the least matters to anybody else."

Lady Barmouth came into the room at the same moment with an intimation that Claire was up in the drawing-room, and would like to see Jack as soon as he was at liberty. Jack went off with alacrity. There was a soothing feeling now that no obstacle any longer stood in his path. He had no fear of the future, so far as Claire was concerned, Anstruther being once out of the way. It was only at this moment, with the knowledge of a placid future before him, that Jack realized how great the mental strain had been.

He found Claire waiting for him in the drawing-room. She advanced with a smile upon her face, and he took her in his arms and kissed her, feeling at last that she was his own, and that there was no shadow of further crime between them. He was just a little grave and silent, and love's quick eyes were there to detect the sombre shade on his face. Very quietly Jack told Claire all that had happened. It was some little time before either spoke.

"I am glad to find that your fortune is intact, my dearest girl," Jack said. "I shall have to work hard now, so that when the good time comes I shall be able to marry you, feeling that my position is equal to your own. It must not be said----"

"It is not going to be said," Claire replied, looking up into her lover's face with a winning smile. "Jack dear, I know exactly what is running in that silly head of yours. I can see I shall have to be very severe with you. Now answer me a question, sir."

"A dozen if you like," Jack replied. "What is it?"

"Well, about the time we first met, and you were so foolish as to fall in love with me. Confess it now: did not you regard me as a poor dependent of Mr. Anstruther's, without so much as a penny of my own? I knew that you loved me long before you told me so--I felt it here at my heart. And yet when you asked me to be your wife, not so many weeks ago, and suggested we should keep the matter a secret as we were too poor to marry, you did not know then that I was an heiress in a small way."

"I am prepared to admit it," Jack said. "But you see, my darling, it is pretty certain that some people----"............