From Place to Place by Irvin S. Cobb

Spy stories rather went out of fashion when the armistice was signed. But this one could not have been told before now, because it happened after the armies had quit fighting and while the Peace Conference was busily engaged in belying its first name. Also, in a strict manner of speaking, it is not a spy story at all.

So far as our purposes are concerned, it began to happen on an afternoon at the end of the month of March of this present year, when J. J. Mullinix, of the Secret Service, called on Miss Mildred Smith, the well-known interior decorator, in her studio apartments on the top floor of one of the best-looking apartment houses in town. For Mullinix there was a short delay downstairs because the doorman, sharp on the lookout to bar pestersome intruders who might annoy the tenants, could not at first make up his mind about Mullinix. In this building there was a rule against solicitors, canvassers, collectors, pedlar men and beggar men; also one against babies, but none against dogs -- excepting dogs above a certain specified size, which -- without further description -- should identify our building as one standing in what is miscalled the exclusive residential belt of Manhattan Island.