The Valley of Fear, Scene 10

The hypothesis points to a secret society.

“It gives me the impression of a secret society of some sort; the same with his badge upon the forearm.” “That’s my idea, too,” said White Mason.

“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?”