Smoke had jumped down from the back of the arm-chair and now occupied the middle of the carpet, where, with tail erect and legs stiff as ramrods, it was steadily pacing backwards and forwards in a narrow space, uttering, as it did so, those curious little guttural sounds of pleasure that only an animal of the feline species knows how to make expressive of supreme happiness. Its stiffened legs and arched back made it appear larger than usual, and the black visage wore a smile of beatific joy. Its eyes blazed magnificently; it was in an ecstasy.
At the end of every few paces it turned sharply and stalked back again along the same line, padding softly, and purring like a roll of little muffled drums. It behaved precisely as though it were rubbing against the ankles of some one who remained invisible. A thrill ran down the doctor’s spine as he stood and stared. His experiment was growing interesting at last.
He called the collie’s attention to his friend’s performance to see whether he too was aware of anything standing there upon the carpet; and the dog’s behaviour was significant and corroborative. He came as far as his master’s knees and then stopped dead, refusing to investigate closely. In vain Dr. Silence urged him; he wagged his tail, whined a little, and stood in a half-crouching attitude, staring alternately at the cat and at his master’s face. He was, apparently, both puzzled and alarmed, and the whine went deeper and deeper down into his throat till it changed into an ugly snarl of awakening anger.
Then the doctor called to him in a tone of command he had never known to be disregarded; but still the dog, though springing up in response, declined to move nearer. He made tentative motions, pranced a little like a dog about to take to water, pretended to bark, and ran to and fro on the carpet. So far there was no actual fear in his manner, but he was uneasy and anxious, and nothing would induce him to go within touching distance of the walking cat. Once he made a complete circuit, but always carefully out of reach; and in the end he returned to his master’s legs and rubbed vigorously against him. Flame did not like the performance at all: that much was quite clear.