Grey Mask

By Patricia Wentworth

Charles never knew why his fiancee dumped him just a few days before their wedding. In anger, he left home for several years. When he finally returned, he was surprised to discover that she was unmarried and barely getting by as a sales clerk in a hat shop. He had always thought she jilted him for another man.
Meanwhile, society is buzzing over the recent death of wealthy Edward Standing, swept overboard at sea and presumed drowned. He left no will and his only child, beautiful, young Margot has no papers to prove she is his child or that her parents were ever married. And if she can't produce her parents' marriage certificate, her cousin Egbert gets everything.
Charles, who is currently staying at a hotel, pays an unannounced visit to his house, a house that is supposed to be empty, with only his caretaker in residence. Charles, arriving at the house, finds the garden gate and the back door both unlocked. Thinking to surprise a burgler, he creeps in and finds no burgler but a criminal gang, led my an anonymous man in a grey mask, in the midst of a plot. They are plotting to get rid of some girl before she can produce "the certificate." (Charles later realizes that they were talking about Margot Standing.) He decides he will go get the police when his ex-fiancee joins the gang. When he realizes she is involved, he changes his mind about informing the police. Charles and his ex will end up trying to protect Margot from those out to get rid of her, with the help of Miss Silver, a private investigator.

This is the first story in the Miss Silver series. It was written in the late 1920s. Miss Silver is an older British woman, similar to Agatha Christie's Miss Marple but Miss Silver is a professional investigator who works discretely to bring miscreants to justice with the minimum of scandal.
I liked this book a lot. The plot is interesting, the characters are pleasant and familiar, and it has secrets aplenty waiting to be revealed, with a couple of romances for another element of interest. And despite it having been written more than eighty years ago, it holds up really well. It was a good, and at times, even humorous story.