For the salt he had eaten (Talbot Mundy)

Almost unknown today, Footner was a Candadian journalist and author of many adventure and mystery novels. His first works were primarily travelogues of various river trips in Canada and the U.S., although he did produce some adventure novels. He is also credited with introducing the first American female investigator in Madame Storey and her plain assistant who explains the evolving solutions to her boss’ cases. So we are introduced to the fascinating Madame Rosika Storey, fearless and intelligent, who plays cat-and-mouse with killers, goes undercover to break up criminal gangs, and unravels deadly mysteries. This is the third book of the succesful mystery series Madame Storey, by canadian-american author Hulbert Footner.