Strong Poison by Dorothy L Sayers

"Well now," said Wimsey, "why do people kill people?"

He was sitting in Miss Katharine Climpson's private office. The establishment was ostensibly a typing bureau, and indeed there were three efficient female typists who did very excellent work for authors and men of science from time to time. Apparently the business was a large and flourishing one, for work frequently had to be refused on the ground that the staff was working at full pressure. But on other floors of the building there were other activities. All the employees were women -- mostly elderly, but a few still young and attractive -- and if the private register in the steel safe had been consulted, it would have been seen that all these women were of the class unkindly known as "superfluous. " There were spinsters with small fixed incomes, or no income at all; widows without family; women deserted by peripatetic husbands and living on a restricted alimony, who, previous to their engagement by Miss Climpson, had had no resources but bridge and boardinghouse gossip. There were retired and disappointed schoolteachers; out-of-work actresses; courageous people who had failed with hat shops and tea parlours; and even a few Bright Young Things, for whom the cocktail party and the nightclub had grown boring. These women seemed to spend most of their time in answering advertisements. Unmarried gentlemen who desired to meet ladies possessed of competences, with a view to matrimony; sprightly sexagenarians, who wanted housekeepers for remote country districts; ingenious gentlemen with financial schemes on the lookout for capital; literary gentlemen, anxious for female collaborators; plausible gentlemen about to engage talent for productions in the provinces; benevolent gentlemen, who could tell people how to make money in their spare time -- gentlemen such as these were very liable to receive applications from members of Miss Climpson's staff. It may have been coincidence that these gentlemen so very often had the misfortune to appear shortly afterwards before the magistrate on charges of fraud, blackmail or attempted procuration, but it is a fact that Miss Climpson's office boasted a private telephone line to Scotland Yard, and that few of her ladies were quite so unprotected as they appeared. It is also a fact that the money which paid for the rent and upkeep of the premises might, by zealous enquirers, have been traced to Lord Peter Wimsey's banking account. His lordship was somewhat reticent about this venture of his, but occasionally, when closeted with Chief Inspector Parker or other intimate friends, referred to it as "My Cattery."