Rich Man, Poor Man by Maximilian Foster

Promptly at six every week-day evening in the year Mr. Mapleson came down the stairs of the L road station on the corner and trudged up the side street toward his home. He lived at Mrs. Tilney’s, the last house but one in the block; but though for more than sixteen years Mr. Mapleson had boarded there, none of the landlady’s other patrons—or the landlady either, for that matter—knew much about their fellow-guest. Frankly he was a good deal of a puzzle. The others thought him queer in his ways besides. They were right perhaps.
—from this Book