Two more policemen had come up, the crowd gathered, humming from all quarters, and the officers had as much as they could do to keep the curious at a distance. The three lanterns were flashing here and there, searching for more evidence, and in the gleam of one of them Dyson caught sight of an object in the road, to which he called the attention of the policeman nearest to him.

'Look, Phillipps,' he said, when the man had secured it and held it up. 'Look, that should be something in your way!'

It was a dark flinty stone, gleaming like obsidian, and shaped to a broad edge something after the manner of an adze. One end was rough, and easily grasped in the hand, and the whole thing was hardly five inches long. The edge was thick with blood.

'What is that, Phillipps?' said Dyson; and Phillipps looked hard at it.

'It's a primitive flint knife,' he said. 'It was made about ten thousand years ago. One exactly like this was found near Abury, in Wiltshire, and all the authorities gave it that age.'

The policeman stared astonished at such a development of the case; and Phillipps himself was all aghast at his own words. But Mr. Dyson did not notice him. An inspector who had just come up and was listening to the outlines of the case, was holding a lantern to the dead man's head. Dyson, for his part, was staring with a white heat of curiosity at something he saw on the wall, just above where the man was lying; there were a few rude marks done in red chalk.

'This is a black business,' said the inspector at length: 'does anybody know who it is?'

A man stepped forward from the crowd. 'I do, governor,' he said, 'he's a big doctor, his name's Sir Thomas Vivian; I was in the 'orspital abart six months ago, and he used to come round; he was a very kind man.'

'Lord,' cried the inspector, 'this is a bad job indeed. Why, Sir Thomas Vivian goes to the Royal Family. And there's a watch worth a hundred guineas in his pocket, so it isn't robbery.'

Dyson and Phillipps gave their cards to the authority, and moved off, pushing with difficulty through the crowd that was still gathering, gathering fast; and the alley that had been lonely and desolate now swarmed with white staring faces and hummed with the buzz of rumour and horror, and rang with the commands of the officers of police. The two men once free from this swarming curiosity stepped out briskly, but for twenty minutes neither spoke a word.

'Phillipps,' said Dyson, as they came into a small but cheerful street, clean and brightly lit, 'Phillipps, I owe you an apology. I was wrong to have spoken as I did to-night. Such infernal jesting,' he went on, with heat, 'as if there were no wholesome subjects for a joke. I feel as if I had raised an evil spirit.'

'For Heaven's sake say nothing more,' said Phillipps, choking down horror with visible effort. 'You told the truth to me in my room; the troglodyte, as you said, is still lurking about the earth, and in these very streets around us, slaying for mere lust of blood.'

'I will come up for a moment,' said Dyson, when they reached Red Lion Square, 'I have something to ask you. I think there should be nothing hidden between us at all events.'

Phillipps nodded gloomily, and they went up to the room, where everything hovered indistinct in the uncertain glimmer of the light from without.

When the candle was lighted and the two men sat facing each other, Dyson spoke.

'Perhaps,' he began, 'you did not notice me peering at the wall just above the place where the head lay. The light from the inspector's lantern was shining full on it, and I saw something that looked queer to me, and I examined it closely. I found that some one had drawn in red chalk a rough outline of a hand—a human hand—upon the wall. But it was the curious position of the fingers that struck me; it was like this'; and he took a pencil and a piece of paper and drew rapidly, and then handed what he had done to Phillipps. It was a rough sketch of a hand seen from the back, with the fingers clenched, and the top of the thumb protruded between the first and second fingers, and pointed downwards, as if to something below.

'It was just like that,' said Dyson, as he saw Phillipps's face grow still whiter. 'The thumb pointed down as if to the body; it seemed almost a live hand in ghastly gesture. And just beneath there was a small mark with the powder of the chalk lying on it—as if someone had commenced a stroke and had broken the chalk in his hand. I saw the bit of chalk lying on the ground. But what do you make of it?'

'It's a horrible old sign,' said Phillipps—'one of the most horrible signs connected with the theory of the evil eye. It is used still in Italy, but there can be no doubt that it has been known for ages. It is one of the survivals; you must look for the origin of it in the black swamp whence man first came.'

Dyson took up his hat to go.

'I think, jesting apart,' said he, 'that I kept my promise, and that we were and are hot on the scent, as I said. It seems as if I had really shown you primitive man, or his handiwork at all events.'

Incident of the Letter

About a month after the extraordinary and mysterious murder of Sir Thomas Vivian, the well-known and universally respected specialist in heart disease, Mr. Dyson called again on his friend Mr.