The detective produced a note-book.
“It is all here,” he said, turning over the leaves. “A Japanese Samurai, or gentleman, in former days carried two swords, one long blade for use against his enemies, and a shorter one for committing suicide if he was beaten or disgraced. The sword Mr. Hume gave his cousin was a short one, and the knife which accompanied it is called the Ko-Katana, or little sword. As well as I could understand Mr. Okasaki, a Jap uses this as a pen-knife, and also as a queer sort of visiting-card. If he slays an enemy he sticks the Ko-Katana between the other fellow’s ribs, or into his ear, and leaves it there.”
“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.”