It must not be thought that, because they achieved no result, the police were lax in their attempts to discover the perpetrator or perpetrators of that cruel crime. To employ again that well-worn phrase, not a stone was left unturned to arrive at an understanding of the manner in which the deed was done. One thing was quite certain, it had been carefully planned; but then so had the disappearance of Woller and the Colonial Secretary. The destruction of Woolwich Arsenal was a work of devilish ingenuity; while the blowing up of the transport Sultan of Sedang at Madeira was arranged to a nicety. In the case of the Prime Minister, the servants and members of his household were interrogated, but were all dismissed from the case as being beyond suspicion. They unitedly declared that, to the best of their belief, no stranger had entered the house up to the time of their going to bed, nor had any suspicious person been seen in its vicinity during the day. Moreover, the police on duty in the Square had been instructed to keep a watchful eye upon the house, and they were able to affirm that they had seen no one loitering near the Prime Minister's residence from the earliest hours of morning until the time that the news of the tragedy was made known. Yet the fact remained that some one had entered the house, and had been able to make his way unobserved to the library, where the crime was committed, and afterwards to get out again undiscovered. Needless to say, a large reward was offered by the authorities for any information which would lead to a conviction; but though a multitude of communications were received in answer to it, from all sorts and conditions of people, not one was of any value.

On the Friday following the assassination of the Prime Minister, and the day before the funeral, according to custom I took a constitutional in the Park before going down to my office. As a matter of fact I was somewhat earlier than usual, and for that reason, with the exception of a few riders in the Row, and the customary bicycle contingent, the Park was comparatively empty. I entered by the Grosvenor Gate, walked as far as the Barracks, and then retraced my steps towards Piccadilly, passing along the north bank of the Serpentine. I had several difficult problems to work out that day, and one of them was occupying my mind as I walked beside the lake. Suddenly a voice I recognised fell upon my ear, and I looked up to find, seated a few paces distant from me, no less a person than the Countess de Venetza. She was engaged in an earnest conversation with a dark, foreign-looking individual, an Italian, without the shadow of a doubt. The Countess did not see me at first, but, as soon as she did, she said something hurriedly to the man beside her and came forward to greet me.

"You are out early, Sir George," she began. "The Park is delightful at this time of the day, is it not?"

"Delightful indeed," I replied. "I did not expect, however, to have the pleasure of meeting you in it."

"I walk here almost every morning," she answered. And then, after we had uttered a few commonplaces, she continued: "And now, while I think of it, let me apologize to you for my rudeness in having omitted to thank you again for the great service you rendered us on the occasion of the burglary at Wiltshire House. Had it not been for your prompt action, we should have been more seriously robbed, while it is quite possible that something worse might have happened."

"You say that you might have been 'more seriously robbed'?" I returned. "Am I to understand, then, that the man was found in the house after all?"

"He was not found in the house," she replied. "But we have discovered by what means he effected his escape from it. While Conrad and the police were looking for him downstairs, he was hidden in a dressing-room adjoining that which used to be my father's apartment, at the back of the house. When they ascended the stairs he opened the window and lowered himself down to a roof below. Then he must have made his way through the mews at the back and reached safety again. In proof of this a small silver ornament, one of the few missing things, was found next day in the guttering of the roof."

If this were so, then the detective's statement to the effect that the man who had entered the house was none other than young Reiffenburg was altogether beyond the mark, and would only serve to show the folly of judging by purely circumstantial evidence.