The bundle sniffed in an affirmative manner, so Stewart opened the letter and read it quickly. It only contained a line from Naball that if he heard of any new development of the case he would let Keith know, so that young gentleman, wondering why the detective took the trouble to write to him slipped the letter in his pocket, and nodded to the bundle. "All right," he said quickly; "no answer," and he shut the door in the bundle's face, whereupon the bundle sniffed. "I know him now," said Mr. Tulch to himself in a husky voice, as he walked away. "I'd know 'im if he was dooplicated twice h'over." Having come to this satisfactory conclusion, Mr. Tulch took up his position a short distance away, and began his dreary task of watching the house. And it was dreary work. The long hot day was over, and the long hot night had begun. It was just a quarter past seven, and the sky was a cloudless expanse of darkish blue, blazing with stars; a soft wind was whispering among the leaves of the trees, and making little whirls of white dust in the road. Every now and then a gay party of men and women on their way to some amusement would pass the spy, but he remained passively at his post, watching the sun-blistered varnished door of Vance's boarding-house. At last his patience was rewarded, for, somewhere about half-past seven, Keith came hurriedly out, and sped rapidly down the street. "What's he arter?" sniffed Mr. Tulch, stretching his cramped limbs. "I'll 'ave to ketch 'im h'up," and he rolled as quickly as he was able after the tall figure of the young man. A tram came along, and, without stopping it, Keith jumped on the dummy--the spy, breathless with running, sprang on the step of the end car and got inside, keeping his eye on Keith. The tram car went rapidly along Flinders Street, stopping every now and then to pick up or drop passengers, at which Keith seemed impatient. At last Spencer Street station was reached, and Keith sprang out; so did Tulch, keeping close to his heels. Stewart walked impatiently up and down one of the long platforms, which shortly began to fill with people expecting their friends. The shrill whistle of an approaching engine was heard, a red light suddenly appeared, advancing rapidly, and presently the long train, with its lighted carriages, drew up inside the station. Such a hurry-scurry; people jumping out of the train to meet those pressing forward on the platform, porters calling to one another, boxes, rugs, portmanteaus, bundles, all strewing the ground--a babel of voices, and at intervals the shrill whistle of a departing train.