I stooped down and picked it up and whipped it into my pocket, and I was just about to walk on when I heard again that sound of dashing footsteps. I don't know why I did it, but as a matter of fact I dived down into the mews, or whatever it was, and stood as much in the shadow as possible. A man went by with a rush a few paces from where I was standing, and I felt uncommonly pleased that I was in hiding. I couldn't make out much feature, but I saw his eyes gleaming and his teeth showing, and he had an ugly-looking knife in one hand, and I thought things would be very unpleasant for gentleman number one if the second robber, or robbed, or what you like, caught him up. I can tell you, Phillipps, a fox hunt is exciting enough, when the horn blows clear on a winter morning, and the hounds give tongue, and the red-coats charge away, but it's nothing to a man hunt, and that's what I had a slight glimpse of to-night. There was murder in the fellow's eyes as he went by, and I don't think there was much more than fifty seconds between the two. I only hope it was enough."

Dyson leant back in his armchair and relit his pipe, and puffed thoughtfully. Phillipps began to walk up and down the room, musing over the story of violent death fleeting in chase along the pavement, the knife shining in the lamplight, the fury of the pursuer, and the terror of the pursued.

"Well," he said at last, "and what was it, after all, that you rescued from the gutter?"

Dyson jumped up, evidently quite startled. "I really haven't a notion. I didn't think of looking. But we shall see."

He fumbled in his waistcoat pocket and drew out a small and shining object, and laid it on the table. It glowed there beneath the lamp with the radiant glory of rare old gold; and the image and the letters stood out in high relief, clear and sharp, as if it had but left the mint a month before. The two men bent over it, and Phillipps took it up and examined it closely.

"Imp. Tiberius Cæsar Augustus," he read the legend, and then, looking at the reverse of the coin, he stared in amazement, and at last turned to Dyson with a look of exultation.

"Do you know what you have found?" he said.

"Apparently a gold coin of some antiquity," said Dyson, coolly.

"Quite so, a gold Tiberius. No, that is wrong. You have found the gold Tiberius. Look at the reverse."

Dyson looked and saw the coin was stamped with the figure of a faun standing amidst reeds and flowing water. The features, minute as they were, stood out in delicate outline; it was a face lovely and yet terrible, and Dyson thought of the well-known passage of the lad's playmate, gradually growing with his growth and increasing with his stature, till the air was filled with the rank fume of the goat.

"Yes," he said, "it is a curious coin. Do you know it?"

"I know about it. It is one of the comparatively few historical objects in existence; it is all storied like those jewels we have read of. A whole cycle of legend has gathered round the thing; the tale goes that it formed part of an issue struck by Tiberius to commemorate an infamous excess. You see the legend on the reverse: 'Victoria.' It is said that by an extraordinary accident the whole issue was thrown into the melting pot, and that only this one coin escaped. It glints through history and legend, appearing and disappearing, with intervals of a hundred years in time and continents in place. It was discovered by an Italian humanist, and lost and rediscovered. It has not been heard of since 1727, when Sir Joshua Byrde, a Turkey merchant, brought it home from Aleppo, and vanished with it a month after he had shown it to the virtuosi, no man knew or knows where. And here it is!"

"Put it into your pocket, Dyson," he said, after a pause. "I would not let any one have a glimpse of the thing, if I were you. I would not talk about it. Did either of the men you saw see you?"

"Well, I think not. I don't think the first man, the man who was vomited out of the dark passage, saw anything at all; and I am sure that the second could not have seen me."

"And you didn't really see them.