Two years passed by after my return to London without special incident, save that my black cat died. My work as a consulting physician occupied most of my time. In the greater world beyond my consulting-room door life went on undisturbed by any thought of the approaching upheaval, full of the old tragedies of ambition and love and sickness. But sometimes as I examined my patients and listened to their tales of suffering and pain, a curious contraction of the heart would come upon me at the thought that perhaps some day, not so very far remote, all the endless cycle of disease and misery would cease, and a new dawn of hope burst with blinding radiance upon weary humanity. And then a mood of unbelief would darken my mind and I would view the creation of the bacillus as an idle and vain dream, an illusion never to be realized.... One evening as I sat alone before my study fire, my servant entered and announced there was a visitor to see me. "Show him in here," I said, thinking he was probably a late patient who had come on urgent business. A moment later Professor Sarakoff himself was shown in. I rose with a cry of welcome and clasped his hand. "My dear fellow, why didn't you let me know you were coming?" I cried. He smiled upon me with a mysterious brightness. "Harden," he said in a low voice, as if afraid of being heard, "I came on a sudden impulse. I wanted to show you something. Wait a moment." He went out into the hall and returned bearing a square box in his hands. He laid it on the table and then carefully closed the door. "It is the first big result of my experiments," he whispered. He opened the box and drew out a glass case covered over with white muslin. He stepped back from the table and looked at me triumphantly. "What is it?" I asked. "Lift up the muslin." I did so. On the wooden floor of the glass case were a great number of dark objects. At first I thought they were some kind of grub, and then on closer inspection I saw what they were. "Butterflies!" I exclaimed. He held up a warning finger and tiptoed to the door. He opened it suddenly and seemed relieved to find no one outside. "Hush!" he said, closing the door again. "Yes, they are butterflies." He came back to the table and gave one of the glass panels a tap with his finger. The butterflies stirred and some spread their wings. They were a brilliant greenish purple shot with pale blue. "Yes, they are butterflies." I peered at them. "The specimen is unknown in England as far as I know." "Quite so. They are peculiar to Russia." "But what are you doing with them?" I asked. He continued to smile. "Do you notice anything remarkable about these butterflies?" "No," I said after prolonged observation, "I can't say I do ... save that they are not denizens of this country."