Furneaux repocketed the skull, and was gazing moodily at the report, when a uniformed constable announced that a boy messenger wished to see a “detective” with regard to the typed letter delivered at Mr. Forbes’s house on Wednesday evening.

“Show him up,” said the chief, and a smart-looking boy, wearing the familiar uniform of his corps, was brought in.  He glanced around inquiringly.

“Oh, you’re the gentleman who came to our Piccadilly office,” he said to Winter.

“Yes.”

“Well, sir, I haven’t very much to tell you, but it was I who took the letter to Fortescue Square.  I saw the sender, a foreign-looking gentleman, he was, with funny eyes, and I think I spotted him again this afternoon.  He was coming out of a house in Charlotte Street.”

“Are you sure?” demanded Winter, quickly.

“He was awful like the man who engaged me, sir, and dressed the same way.”

“Did you notice the number of the house?”

“Yes, sir.  No. 412.”

“Quite certain about that?”

“Yes, sir.”

“Good boy.  If your information is of any service I’ll take care you are not forgotten.”

The boy saluted and went out.

“We must look up No. 412,” said Winter, quietly; but there was a ring of genuine satisfaction in his voice, because the clew promised well, and it was a complete justification of the straightforward method he adopted in every inquiry, whereas Furneaux invariably preferred an abstruse theory to a definite piece of evidence.

The Jersey man’s face had wrinkled as a preliminary to some sarcastic comment on what he termed the “handcuff” way of reasoning, when the telephone bell rang.  Winter answered, and at once his self-possessed air fled.  Indeed, it was a very angry man who listened, because a subordinate was telephoning from Fortescue Square a full account of the shooting outrage.

The Chief gave a few curt instructions as to securing the adequate cooperation of the local police, who should take measures to render any repetition of such daring tactics absolutely impossible.

“No one was injured, you say?” he added.

“No, sir.”

“Were the ladies very much frightened?”

“They’ve gone back to finish luncheon, sir.”

“Good.  Evidently they’re all of the right breed.  You can tell them I said so, if you like.  Assure Mr. Forbes that every care will be taken to protect his house in future.  See that strong patrols occupy every point from which a gun can be aimed at any window, even the attics, in No. 11.  Phone me again when you have discussed matters with the district superintendent.”

The receiver clanged back into its hook.  Winter had not foreseen this latest move.  “Sheer impudence,” he termed it.

“More bullets?” inquired Furneaux laconically.

“Yes.  A long-range attack from across the square.  Four shots lodged in dining room.”