The House of the Schemers by Fred M. White

Inspector John Burles had lunched comfortably in his own rooms, where he was enjoying a cigarette before commencing the work of the afternoon. He had a case after his own heart; the thing was working out very well, and on the whole Burles was satisfied with himself. His methods were not quite those of the ordinary detective, which perhaps accounted for the success that usually attended his efforts. It was no bad thing to be a gentleman and a man of education, and Burles was a specialist in crime.

But up to now he had had few cases so much after his own heart as the mystery at No. 14, Vernon-terrace. The thing was so complicated and so apparently inexplicable that Burles was fairly revelling in it.