"We hark back now to the point at which we left Constable Nightingale. He had returned to Gerard Street without having found the man. During his absence nothing further had occurred to alarm the housekeeper and the constable who kept her company, and they were in doubt as to what was best to be done. There was no evidence that the man had entered the house with the intention of robbing it, but he might have done so, and being disturbed before he effected his purpose, thought it expedient to make his escape as quickly as possible. They were debating this view when they were startled by what they declare was an 'apparition.' It was the apparition of a half-starved cat, which in some way must have found an entrance into the house before Mrs. Middlemore came back with her supper-beer. The cat did not belong to the house, for M. Felix had a horror of such creatures, and would not allow one to be kept on the premises. It was not the cat that startled them, but the color of the cat, which seemed to have been rolling itself in blood. They saw it only for an instant, and then it disappeared, and has not since been seen again; but it left its marks behind it. On the oil-cloth were marks of blood, made by the cat's paws. These signs decided their course of action, and they proceeded upstairs to the apartments occupied by M. Felix. They knocked and called out loudly to him, but received no answer. By an ingenious arrangement, devised presumably by M. Felix himself, the keyhole of the door by which they stood was masked by a brass plate, the secret of which was known only to M. Felix. The silence strengthened their apprehensions of foul play, and they determined to force the door open. To effect this it was necessary to obtain the assistance of a locksmith, and Constable Nightingale issued forth once more, and brought back with him not only a locksmith, but a doctor in the neighborhood, Dr. Lamb, who was coming home late from a professional visit. With some difficulty the door was forced open, and the first thing that met their eyes was a pool of blood on the floor of the sitting-room. They describe it as such, although subsequent examination proved that there was a decided exaggeration in calling it a pool, the quantity of blood which had fallen not being very serious. M. Felix was not in this room, but when they entered the bedroom adjoining they discovered him in an arm-chair, bearing the appearance of a man who had fallen asleep. He was not asleep, however; he was dead. The natural presumption was that he had been murdered, and that the blood on the floor was his, but Dr. Lamb very soon declared that this was not the case. M. Felix was dead, certainly, but his death was produced by natural causes, heart disease. In this conclusion Dr. Lamb was supported by other medical evidence which was sought on the following day, and this being supposed to be sufficiently established, the necessity of a post-mortem was not immediately recognized. The