Note Book of an English Opium-Eater by De Quincey, Thomas, 1785-1859

To this young woman it was, that, suddenly, within three or four minutes of midnight, Marr called aloud from the head of the stairs--directing her to go out and purchase some oysters for the family supper. Upon what slender accidents hang oftentimes solemn lifelong results! Marr occupied in the concerns of his shop, Mrs. Marr occupied with some little ailment and restlessness of her baby, had both forgotten the affair of supper; the time was now narrowing every moment, as regarded any variety of choice; and oysters were perhaps ordered as the likeliest article to be had at all, after twelve o'clock should have struck. And yet, upon this trivial circumstance depended Mary's life. Had she been sent abroad for supper at the ordinary time of ten or eleven o'clock, it is almost certain that she, the solitary member of the household who escaped from the exterminating tragedy, would _not_ have escaped; too surely she would have shared the general fate. It had now become necessary to be quick. Hastily, therefore, receiving money from Marr with a basket in her hand, but unbonneted, Mary tripped out of the shop. It became afterwards, on recollection, a heart-chilling remembrance to herself--that, precisely as she emerged from the shop-door, she noticed, on the opposite side of the street, by the light of the lamps, a man's figure; stationary at the instant, but in the next instant slowly moving. This was Williams; as a little incident, either just before or just after (at present it is impossible to say which), sufficiently proved. Now, when one considers the inevitable hurry and trepidation of Mary under the circumstances stated, time barely sufficing for any chance of executing her errand, it becomes evident that she must have connected some deep feeling of mysterious uneasiness with the movements of this unknown man; else, assuredly, she would not have found her attention disposable for such a case. Thus far, she herself threw some little light upon what it might be that, semi- consciously, was then passing through her mind; she said, that, notwithstanding the darkness, which would not permit her to trace the man's features, or to ascertain the exact direction of his eyes, it yet struck her, that from his carriage when in motion, and from the apparent inclination of his person, he must be looking at No. 29.