My friend rose lazily from his armchair and stood with his hands in the pockets of his dressing-gown, looking over my shoulder. It was a bright, crisp February morning, and the snow of the day before still lay deep upon the ground, shimmering brightly in the wintry sun. Down the centre of Baker Street it had been ploughed into a brown crumbly band by the traffic, but at either side and on the heaped-up edges of the footpaths it still lay as white as when it fell. The grey pavement had been cleaned and scraped, but was still dangerously slippery, so that there were fewer passengers than usual. Indeed, from the direction of the Metropolitan Station no one was coming save the single gentleman whose eccentric conduct had drawn my attention.