A. E. W. Mason

“ It looked as if Ann Upcott was wilfully pushing her neck into the wooden ring of the guillotine.
Hanaud shook his head.
"Not so mad, my friend! The old rules are the best. Hide a thing in some out-of-the-way corner, and it will surely be found. Put it to lie carelessly under every one's nose and no one will see it at all. No, no! This was cleverly done. Who could have foreseen that instead of looking on at our search you were going to plump yourself down in a chair and write your memorandum so valuable on Mademoiselle Ann's notepaper? And even then you did not notice your pen. ”

“ He looked up with relief.
"There is not the least little trace of that reddish-brown clay which made the poison paste. The arrow was scraped clean before it was put on that tray of pens. I am enchanted. I cannot now afford to lose my junior colleague."
Frobisher drew a long breath and lit a cigarette, and gave another proof that he was a very novice of a bull.
"What a mad thing to put the head of that arrow-shaft, which a glance at the plates in the Treatise would enable a child to identify, into an open tray of pens without the slightest concealment!" he exclaimed. ”

“ He removed the nib from the arrow-head.
"We will keep this little matter to ourselves just for the moment," he said quickly, and he wrapped the improvised pen-holder in a sheet of the notepaper. "Just you and I shall know of it. No one else. This is my case, not Girardot's. We will not inflict a great deal of pain and trouble until we are sure."
"I agree," said Jim eagerly. "That's right, I am sure."
Hanaud tucked the arrow-head carefully away in his pocket.
"This, too," he said, and he took up Jim Frobisher's memorandum. "It is not a good thing to carry about, and perhaps lose. ”

“ What was it that he had in his mind to say to me at the Café in the Place d'Armes and in the end did not say? (4) Why did Hanaud search every corner of the treasure-room for the missing poison arrow—except the interior of the sedan chair? The noise of a door gently closing aroused him from his speculations. He looked across the room. Hanaud had just entered it from the bedroom, shutting the communicating door behind him. He stood with his hand upon the door-knob gazing at Frobisher with a curious startled stare. He moved swiftly to the end of the table at which Jim was sitting. ”

“ When the twenty are gone, you will answer them all for yourself. Meanwhile"—he took up another pen and made a tiny addition to item one—"I carry this on one step farther. See!"
He replaced the memorandum under Jim's eyes. Jim read:
"—subsequent developments, e.g. the disappearance of the Poison Arrow, the introduction into the case of the ill-famed Jean Cladel, Ann Upcott's story of her visit to the treasure-room, and now the mystery of Mrs. Harlowe's pearl necklace, and the finding of the arrow, make out a prima facie case for inquiry." ”

“ Harlowe's pearl necklace, make out a prima facie case for inquiry.
Against
But in the absence of any trace of poison in the dead woman's body, it is difficult to see how the criminal can be brought to justice, except by
(a) A confession. (b) The commission of another crime of a similar kind. Hanaud's theory—once a poisoner always a poisoner.
For
(2) If murder was committed, it is probable that it was committed at half-past ten at night when Ann Upcott in the treasure-room heard the sound of a struggle and the whisper, "That will do now." ”

“ All of them have many years of service to their credit. It is not possible that any of them would have understood enough of the "Treatise on Strophanthus Hispidus" to make use of it. If any of them were concerned it can only be as an accessory or assistant working under the direction of another. ”