He was still following these quaint and serious musings when he came into a street of more mingled ingredients than was common in the quarter. Here, on the one hand, framed in walls and the green tops of trees, were several of those discreet, _bijou_ residences on which propriety is apt to look askance. Here, too, were many of the brick-fronted barracks of the poor; a plaster cow, perhaps, serving as ensign to a dairy, or a ticket announcing the business of the mangler. Before one such house, that stood a little separate among walled gardens, a cat was playing with a straw, and Challoner paused a moment, looking on this sleek and solitary creature, who seemed an emblem of the neighbouring peace. With the cessation of the sound of his own steps the silence fell dead; the house stood smokeless: the blinds down, the whole machinery of life arrested; and it seemed to Challoner that he should hear the breathing of the sleepers. As he so stood, he was startled by a dull and jarring detonation from within. This was followed by a monstrous hissing and simmering as from a kettle of the bigness of St. Paul’s; and at the same time from every chink of door and window spirted an ill-smelling vapour. The cat disappeared with a cry. Within the lodging-house feet pounded on the stairs; the door flew back, emitting clouds of smoke; and two men and an elegantly dressed young lady tumbled forth into the street and fled without a word. The hissing had already ceased, the smoke was melting in the air, the whole event had come and gone as in a dream, and still Challoner was rooted to the spot. At last his reason and his fear awoke together, and with the most unwonted energy he fell to running. Little by little this first dash relaxed, and presently he had resumed his sober gait and begun to piece together, out of the confused report of his senses, some theory of the occurrence. But the occasion of the sounds and stench that had so suddenly assailed him, and the strange conjunction of fugitives whom he had seen to issue from the house, were mysteries beyond his plummet. With an obscure awe he considered them in his mind, continuing, meanwhile, to thread the web of streets, and once more alone in morning sunshine. In his first retreat he had entirely wandered; and now, steering vaguely west, it was his luck to light upon an unpretending street, which presently widened so as to admit a strip of gardens in the midst. Here was quite a stir of birds; even at that hour, the shadow of the leaves was grateful; instead of the burnt atmosphere of cities, there was something brisk and rural in the air; and Challoner paced forward, his eyes upon the pavement and his mind running upon distant scenes, till he was recalled, upon a sudden, by a wall that blocked his further progress. This street, whose name I have forgotten, is no thoroughfare.