Robbins, fifty, something of an overweight beau, and addicted to first nights and hotel palm-rooms, pretended to be envious of his partner’s commuter’s joys. “Going to be something doing in the humidity line to-night,” he said. “You out-of-town chaps will be the people, with your katydids and moonlight and long drinks and things out on the front porch.” Hartley, twenty-nine, serious, thin, good-looking, nervous, sighed and frowned a little. “Yes,” said he, “we always have cool nights in Floralhurst, especially in the winter.” A man with an air of mystery came in the door and went up to Hartley. “I’ve found where she lives,” he announced in the portentous half-whisper that makes the detective at work a marked being to his fellow men. Hartley scowled him into a state of dramatic silence and quietude. But by that time Robbins had got his cane and set his tie pin to his liking, and with a debonair nod went out to his metropolitan amusements. “Here is the address,” said the detective in a natural tone, being deprived of an audience to foil. Hartley took the leaf torn out of the sleuth’s dingy memorandum book. On it were pencilled the words “Vivienne Arlington, No. 341 East ––––th Street, care of Mrs. McComus.” “Moved there a week ago,” said the detective. “Now, if you want any shadowing done, Mr. Hartley, I can do you as fine a job in that line as anybody in the city. It will be only $7 a day and expenses. Can send in a daily typewritten report, covering—” “You needn’t go on,” interrupted the broker. “It isn’t a case of that kind. I merely wanted the address. How much shall I pay you?” “One day’s work,” said the sleuth. “A tenner will cover it.” Hartley paid the man and dismissed him. Then he left the office and boarded a Broadway car. At the first large crosstown artery of travel he took an eastbound car that deposited him in a decaying avenue, whose ancient structures once sheltered the pride and glory of the town. Walking a few squares, he came to the building that he sought. It was a new flathouse, bearing carved upon its cheap stone portal its sonorous name, “The Vallambrosa.” Fire-escapes zigzagged down its front—these laden with household goods, drying clothes, and squalling children evicted by the midsummer heat. Here and there a pale rubber plant peeped from the miscellaneous mass, as if wondering to what kingdom it belonged—vegetable, animal or artificial. Hartley pressed the “McComus” button. The door latch clicked spasmodically—now hospitably, now doubtfully, as though in anxiety whether it might be admitting friends or duns. Hartley entered and began to climb the stairs after the manner of those who seek their friends in city flat-houses—which is the manner of a boy who climbs an apple-tree, stopping when he comes upon what he wants.