attention. We beg to remain,
"Yours, etc.,
"Fradley & Toomer,
"470 Regent Square, London, S. W."
The next letter was even less interesting. It merely stated that the money had been received and the book would be forwarded. The third engaged my attention, and I shall quote it, the translation being a free one:
"Dear Sir: Your letter of the 1st of July was duly received, and we at once referred it to Mr. Fradley himself. Mr. Fradley being much interested in your question, sent your letter to Professor Schweineri, of the Berlin Entomological Society, whose note Blowzer refers to on page 630, in his How to catch British Butterflies. We have just received an answer from Professor Schweineri, which we translate into French – (see inclosed slip). Professor Schweineri begs to present to you two jars of cythyl, prepared under his own supervision. We forward the same to you. Trusting that you will find everything satisfactory, we remain,
"Yours sincerely,
"Fradley & Toomer."
The inclosed slip read as follows:
"Messrs. Fradley & Toomer,
"Gentlemen: Cythaline, a complex hydrocarbon, was first used by Professor Schnoot, of Antwerp, a year ago. I discovered an analogous formula about the same time and named it cythyl. I have used it with great success everywhere. It is as certain as a magnet. I beg to present you three small jars, and would be pleased to have you forward two of them to your correspondent in St. Gildas with my compliments. Blowzer's quotation of me, on page 630 of his glorious work, How to catch British Butterflies, is correct.
"Yours, etc.,
"Heinrich Schweineri,
P.H.D., D.D., D.S., M.S."
When I had finished this letter I folded it up and put it into my pocket with the others. Then I opened Blowzer's valuable work, How to catch British Butterflies, and turned to page 630.
Now, although the Red Admiral could only have acquired the book very recently, and although all the other pages were perfectly clean, this particular page was thumbed black, and heavy pencil marks inclosed a paragraph at the bottom of the page. This is the paragraph:
"Professor Schweineri says: 'Of the two old methods used by collectors for the capture of the swift-winged, high-flying Apatura Iris, or Purple Emperor, the first, which was using a long-handled net, proved successful once in a thousand times; and the second, the placing of bait upon the ground, such as decayed meat, dead cats, rats, etc., was not only disagreeable, even for an enthusiastic collector, but also very uncertain. Once in five hundred times would the splendid butterfly leave the tops of his favourite oak trees to circle about the fetid bait offered. I have found cythyl a perfectly sure bait to draw this beautiful butterfly to the ground, where it can be easily captured. An ounce of cythyl placed in a yellow saucer under an oak tree, will draw to it every Apatura Iris within a radius of twenty miles. So, if any collector who possesses a little cythyl, even though it be in a sealed bottle in his pocket – if such a collector does not find a single Apatura Iris fluttering close about him within an hour, let him be satisfied that the Apatura Iris does not inhabit his country.'"
When I had finished reading this note I sat for a long while thinking hard. Then I examined the two jars. They were labelled "Cythyl." One was full, the other nearly full. "The rest must be on the corpse of the Red Admiral," I thought, "no matter if it is in a corked bottle – "
I took all the things back to the chest, laid them carefully on the straw, and closed the lid. The gendarme sentinel at the gate saluted me respectfully as I crossed over to the Groix Inn. The Inn was surrounded by an excited crowd, and the hallway was choked with gendarmes and peasants. On every side they greeted me cordially, announcing that the real murderer was caught; but I pushed by them without a word and ran upstairs to find Lys. She opened her door when I knocked and threw both arms about my neck. I took her to my breast and kissed her. After a moment I asked her if she would obey me no matter what I commanded, and she said she would, with a proud humility that touched me.
"Then go at once to Yvette in St. Julien," I said. "Ask her to harness the dog-cart and drive you to the convent in Quimperlé. Wait for me there. Will you do this without questioning me, my darling?"
She raised her face to mine. "Kiss me," she said innocently; the next moment she had vanished.
I walked deliberately into the Purple Emperor's room and peered into the gauze-covered box which had held the chrysalis of Apatura Iris. It was as I expected. The chrysalis was empty and transparent, and a great crack ran down the middle of its back, but, on the netting inside the box, a magnificent butterfly slowly waved its burnished purple wings; for the chrysalis had given up its silent tenant, the butterfly symbol of immortality. Then a great fear fell upon me. I know now that it was the fear of the Black Priest, but neither then nor for years after did I know that the Black Priest had ever lived on earth. As I bent over the box I heard a confused murmur outside the house which ended in a furious shout of "Parricide!" and I heard the gendarmes ride away behind a wagon which rattled sharply on the flinty highway. I went to the window. In the wagon sat Yves Terrec, bound and wild-eyed, two gendarmes at either side of him, and all around the wagon rode mounted gendarmes whose bared sabres scarcely kept the crowd away.
"Parricide!" they howled. "Let him die!"
I stepped back and opened the gauze-covered box. Very gently but firmly I took the splendid butterfly by its closed fore wings and lifted it unharmed between my thumb and forefinger. Then, holding it concealed behind my back, I went down into the café.
Of all the crowd that had filled it, shouting for the death of Yves Terrec, only three persons remained seated in front of the huge empty fireplace. They were the Brigadier Durand, Max Fortin, the chemist of Quimperlé, and the Purple Emperor. The latter looked abashed when I entered, but I paid no attention to him and walked straight to the chemist.
"Monsieur Fortin," I said, "do you know much about hydrocarbons?"
"They are my specialty," he said astonished.
"Have you ever heard of such a thing as cythyl?"
"Schweineri's cythyl? Oh, yes! We use it in perfumery."
"Good!" I said. "Has it an odour?"
"No – and, yes. One is always aware of its presence, but really nobody can affirm it has an odour. It is curious," he continued, looking at me, "it is very curious you should have asked me that, for all day I have been imagining I detected the presence of cythyl."
"Do you imagine so now?" I asked.
"Yes, more than ever."
I sprang to the front door and tossed out the butterfly. The splendid creature beat the air for a moment, flitted uncertainly hither and thither, and then, to my astonishment, sailed majestically back into the café and alighted on the hearthstone. For a moment I was nonplussed, but when my eyes rested on the Purple Emperor I comprehended in a flash.
"Lift that hearthstone!" I cried to the Brigadier Durand; "pry it up with your scabbard!"
The Purple Emperor suddenly fell forward in his chair, his face ghastly white, his jaw loose with terror.
"What is cythyl?" I shouted, seizing him by the arm; but he plunged heavily from his chair, face downward on the floor, and at the same moment a cry from the chemist made me turn. There stood the Brigadier Durand, one hand supporting the hearthstone,
