Nick Carter inspected the hearth carefully, and at last found a slight impression of a foot which was apparently that which had made the mark on the rug. “He couldn’t have come down the chimney to get into the room,” he decided, after a glance upward. “It would be too hot. This fire is not as large as it was when Anderton was sitting here. No one could come down this way. But the foot? Why?” He made a closer inspection, and then laughed at himself, as if ashamed of his own want of perspicuity. “This foot is straight across the hearth, parallel with the fire. I see how it was. The man was walking past the fireplace, and accidentally one of his feet trod upon the ashes. Well, that is good, so far as it goes. It tells me where he was, and also the kind of footwear he had. But he didn’t come in by way of this flue, wide as it is.” The room was at the back of the house, and heavy curtains were drawn over the windows. Nick Carter flung one of the curtains aside and peered out. He saw that there was a long balcony outside, which passed both windows, and he knew it had been arranged thus for a fire escape. It was not like the ordinary contrivance of that kind, such as is seen on apartment houses and some business buildings. It had been built by the owner of the house, and was of an ornate description, with no ladder leading to the ground. Instead, there was a rope ladder, with steel crosspieces, which could be let down if desired. The ladder was out of reach of any burglar who might get to the back of the premises and seek to get in by way of the study window. The windows were both fastened with spring catches. These fastenings were heavy and of modern pattern. But Nick Carter smiled sadly, as he reflected how easy it would be for a professional cracksman to negotiate them. A thin-bladed knife would be the only tool required. The fellow who had murdered Anderton may not have been a professional burglar, but assuredly he would be ingenious enough to get one of these windows open, and close it again when he had finished his work. The detective, flash lamp in hand, stepped out on the balcony. The floor was of painted steel, and solid. Most fire escapes have a railed floor, but this had been put up under the eye of the dead man, and he wanted it like the floor of a room. Directing the strong, white light of his lamp on the floor of the balcony, Nick Carter did not discover anything that would help him for the first few minutes. Suddenly a low ejaculation of satisfaction escaped him. “By George! Here it is! But what does it mean?” He had found a slight smudge of wood ash at the very end of the balcony. It was so small that it might easily have been overlooked by any but the sharpest eyes. Even the detective had passed it over several times. He knelt down and put the light close to it. Beyond question, there was a gray-white mark, but it bore nothing of the shape of a human foot. “Well, I’ll have to try something else.”