Neat clusters of condiments ornament the tables in the quiet, tobacco-free dining room of South Kensington's Onslow Court Hotel. There, in a silence broken only by the tinkle of chinaware, an occasional polite belch or a muffled platitude, retired colonels and well-to-do widows dine in respectable isolation without recourse to spirits. One of these was stately Mrs. Olive Henrietta Roberts Durand-Deacon, a widow of 69. She had few close friends at the hotel, but over a period of three years had struck up an acquaintance with a youngish (39) gentleman named John George Haigh, who was, he said, an inventor.
Now it...