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."

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