“There seems to be a slight mixture of metaphors in my learned friend’s remarks. But never mind the fog, Jervis. There is a certain virtue in fog. It serves, like a picture frame, to surround the essential with a neutral zone that separates it from the irrelevant.”

“That is a very profound observation, Thorndyke,” I remarked ironically.

“I was just thinking so myself,” he rejoined.

“And if you could contrive to explain what it means⁠—”

“Oh, but that is unreasonable. When one throws off a subtly philosophic obiter dictum one looks to the discerning critic to supply the meaning. By the way, I am going to introduce you to the gentle art of photography this afternoon. I am getting the loan of all the cheques that were drawn by Jeffrey Blackmore during his residence at New Inn⁠—there are only twenty-three of them, all told⁠—and I am going to photograph them.”

“I shouldn’t have thought the bank people would have let them go out of their possession.”