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."
