The conversation of Rupert Grant had two great elements of interest–first, the long fantasias of detective deduction in which he was engaged, and, second, his genuine romantic interest in the life of London. His brother Basil said of him: “His reasoning is particularly cold and clear, and invariably leads him wrong. But his poetry comes in abruptly and leads him right.” Whether this was true of Rupert as a whole, or no, it was certainly curiously supported by one story about him which I think worth telling.
We were walking along a lonely terrace in Brompton together. The street was full of that bright blue twilight which comes about half past eight in summer, and which seems for the moment to be not so much a coming of darkness as the turning on of a new azure illuminator, as if the earth were lit suddenly by a sapphire sun. In the cool blue the lemon tint of the lamps had already begun to flame, and as Rupert and I passed them, Rupert talking excitedly, one after another the pale sparks sprang out of the dusk. Rupert was talking excitedly because he was trying to prove to me the nine hundred and ninety-ninth of his amateur detective theories. He would go about London, with this mad logic in his brain, seeing a conspiracy in a cab accident, and a special providence in a falling fusee. His suspicions at the moment were fixed upon an unhappy milkman who walked in front of us. So arresting were the incidents which afterwards overtook us that I am really afraid that I have forgotten what were the main outlines of the milkman’s crime. I think it had something to do with the fact that he had only one small can of milk to carry, and that of that he had left the lid loose and walked so quickly that he spilled milk on the pavement. This showed that he was not thinking of his small burden, and this again showed that he anticipated some other than lacteal business at the end of his walk, and this (taken in conjunction with something about muddy boots) showed something else that I have entirely forgotten. I am afraid that I derided this detailed revelation unmercifully; and I am afraid that Rupert Grant, who, though the best of fellows, had a good deal of the sensitiveness of the artistic temperament, slightly resented my derision. He endeavoured to take a whiff of his cigar, with the placidity which he associated with his profession, but the cigar, I think, was nearly bitten through.
“My dear fellow,” he said acidly, “I’ll bet you half a crown that wherever that milkman comes to a real stop I’ll find out something curious.”
“My resources are equal to that risk,” I said, laughing. “Done.”
We walked on for about a quarter of an hour in silence in the trail of the mysterious milkman. He walked quicker and quicker, and we had some ado to keep up with him; and every now and then he left a splash of milk, silver in the lamplight. Suddenly, almost before we could note it, he disappeared down the area steps of a house. I believe Rupert really believed that the milkman was a fairy; for a second he seemed to accept him as having vanished. Then calling something to me which somehow took no hold on my mind, he darted after the mystic milkman, and disappeared himself into the area.
I waited for at least five minutes, leaning against a lamp-post in the lonely street. Then the milkman came swinging up the steps without his can and hurried off clattering down the road. Two or three minutes more elapsed, and then Rupert came bounding up also, his face pale but yet laughing; a not uncommon contradiction in him, denoting excitement.