Then I heard him utter words of love, and the sound of a kiss fell upon my ear.

Presently, when he had declared his affection, and she had admitted in faltering tones that she loved him, they rose and passed out into the ball-room. I followed them unobserved.

The man upon whose arm she leaned, radiant and content, was Captain Feodor Matvyèich, a tall fellow of thirty-five, with a well-shaped head, and in whose fiery grey eyes there lurked a joyous twinkle, which told of a right merry nature within. He was the very incarnation of robust, mirthful manhood, and I knew that during the brief period he had been in England he had been exceedingly popular among the attachés. I had no idea, however, that he was the Chief of the Secret Police of Moscow, and that he was in London endeavouring to elucidate some mystery connected with the plot he had discovered.

When, shortly before the dawn, Sophie and I were driving home, I remarked that the Captain was a pleasant fellow, in order to cause her to talk of him.

But with a pre-occupied air she merely answered, “Yes, charming.” Then she turned our conversation into a different channel.

A few days later Matvyèich called, and I was introduced by Sophie as her brother. Soon he became a constant visitor, and we three frequently dined and afterwards went to places of amusement together.

As time went on it was plain that Sophie’s love for him increased, while on his part he adored her, sending her boxes of choice flowers daily, and making her several costly presents of jewellery. I became more puzzled as to the object of her mission by an event which occurred about three weeks later. I had been out during the day, and returned about seven o’clock. As I passed the door of our sitting-room I noticed that it was ajar, and pushing it open, entered noiselessly.

Sophie, who did not notice my entrance, stood facing the fire, bending and examining intently something she held in her hand.

Creeping up behind her, and peeping over her shoulder, I saw, to my surprise, that she held in her hand a morocco case, containing a pretty ornament, evidently intended for the adornment of the hair. It was in the shape of a rapier, the tapering blade being of steel, while the hilt was set with diamonds.