“A P.P.C. card, in fact!”

“You always have some joke against the P.C.’s,” growled the detective.  “I never—­”

“You have just made a most excellent one yourself.  Please continue, Winter.  Your researches are valuable.”

“That is all.  Would you like to see the Ko-Katana that killed Sir Alan?”

“Yes.  Where is it?”

“In the Black Museum at Scotland Yard.  I will take you there.”

“Thank you.  By the way, concerning this man, Okasaki.  Supposing we should want any further information from him on this curious topic, can you find him?  You say he indulged in some liaison with an Ipswich girl, so I assume he has not gone back to Japan.”

“The last I heard of him was at that time.  Some one told me that he was an independent gentleman, noted for his art tastes.  The disappearance of the girl created a rare old row in Ipswich.”

“Make a note of him.  We may need his skilled assistance.  Was there any special design on the Ko-Katana?”

“It was ornamented in some way, but I forget the pattern.”

“I can help you in that matter,” said Hume.  “I remember perfectly that the handle, of polished gun-metal, bore a beautiful embossed design in gold and silver of a setting sun surmounted by clouds and two birds.”

“Correct, Mr. Hume, I recall it now,” said the detective.  “The same thing appears on the handle of the sword.”

Brett ruminated silently on this fresh information.  Like the other pieces in the puzzle, it seemed to have no sort of connection with the cause of the crime.

“Why do you say ‘setting sun’?  How does one distinguish it from the rising sun in embossed or inlaid work?” he asked Hume.

“I do not know.  I only repeat Alan’s remark.  I gave the beastly thing to him because he became interested in Japanese arms during his Eastern tour, you will recollect.”

“Ah, well.  That is a nice point for Mr. Okasaki to settle if we chance to come across him.  Don’t forget, Winter, I want to see that Ko-Katana, Whom did you meet at Sleagill, Hume?”

The young man laughed.  “Helen, of course.”

“Any other person?”

“No.  I told her I might chance to drive out in that direction about five o’clock, so—­”

“Dear me!  You were not at all certain.”

“By no means.  I am at your orders.”

“Excellent!  Then my orders are that you shall meet the young lady on every possible occasion.  You took her for a drive?”

“Well—­er—­yes, I did.  You do not leave me much to tell.”

“Did she say anything of importance—­bearing upon our inquiry, I mean?”

“Nothing.  She had not quitted the rectory since we came away.  I asked her to pick up any village gossip about the people at the Hall, and let us know at the earliest moment if she regarded it as valuable in any way.”

“That was thoughtful of you.  A great deal may happen there at any moment.”