“Well, we can adopt it as a working hypothesis and then see how far our difficulties disappear. An agent from such a society makes his way into the house, waits for Mr. Douglas, blows his head nearly off with this weapon, and escapes by wading the moat, after leaving a card beside the dead man, which will, when mentioned in the papers, tell other members of the society that vengeance has been done. That all hangs together. But why this gun, of all weapons?”

“Exactly.”

“And why the missing ring?”

“Quite so.”

“And why no arrest? It’s past two now. I take it for granted that since dawn every constable within forty miles has been looking out for a wet stranger?”

“That is so, Mr. Holmes.”

“Well, unless he has a burrow close by or a change of clothes ready, they can hardly miss him. And yet they have missed him up to now!” Holmes had gone to the window and was examining with his lens the blood mark on the sill. “It is clearly the tread of a shoe. It is remarkably broad; a splay-foot, one would say. Curious, because, so far as one can trace any footmark in this mud-stained corner, one would say it was a more shapely sole. However, they are certainly very indistinct. What’s this under the side table?”

“Mr. Douglas’s dumb-bells,” said Ames.

“Dumb-bell - there’s only one. Where’s the other?”

“I don’t know, Mr. Holmes. There may have been only one. I have not noticed them for months.”

“One dumb-bell- -” Holmes said seriously; but his remarks were interrupted by a sharp knock at the door.

A tall, sunburned, capable-looking, clean-shaved man looked in at us. I had no difficulty in guessing that it was the Cecil Barker of whom I had heard. His masterful eyes travelled quickly with a questioning glance from face to face.

“Sorry to interrupt your consultation,” said he, “but you should hear the latest news.”

“An arrest?”

“No such luck. But they’ve found his bicycle. The fellow left his bicycle behind him. Come and have a look. It is within a hundred yards of the hall door.”

We found three or four grooms and idlers standing in the drive inspecting a bicycle which had been drawn out from a clump of evergreens in which it had been concealed. It was a well used Rudge-Whitworth, splashed as from a considerable journey. There was a saddlebag with spanner and oilcan, but no clue as to the owner.

“It would be a grand help to the police,” said the inspector, “if these things were numbered and registered. But we must be thankful for what we’ve got. If we can’t find where he went to, at least we are likely to get where he came from. But what in the name of all that is wonderful made the fellow leave it behind? And how in the world has he got away without it? We don’t seem to get a gleam of light in the case, Mr. Holmes.”

“Don’t we?” my friend answered thoughtfully. “I wonder!”