The Whispering Window — Cortland Fitzsimmons

The Whispering Window, first published in 1936, is the first in the series featuring amateur detective Ethel Thomas. The setting is a large department store plagued by missing products and, more seriously, four murders in a single day's time.

From the dustjacket: Meet Miss Ethel Thomas! �" the shrewdest spinster-sleuth that ever walked the pages of a mystery story. You've seldom encountered as lively a lady of her years (age 75), and it's a treat to be taken along with her through the solution of what the newspapers called “The Bargain Day Murders.”

Cortland Fitzsimmons (1893-1949) wrote mysteries, often featuring a sports-theme, some of which were made into movies. He also worked as a screenwriter in Hollywood.