Returning from a trip abroad, the Van Burnam family enters their New York mansion to find a dead woman on the dining room floor. A curio cabinet has fallen on top of her, crushing her face, and law officers suspect that the victim is the wife of one of the Van Burnam sons. However, the son insists that he does not recognize the victim. How did this woman get into this locked house? Whose are those strange garments she is wearing? What is her hat doing in the closet and a strange, gaudy hat crushed underneath her? Why did the coroner insist that the woman was dead when the curio fell? The story itself was another fascinating study in human motivations intertwined with bits and pieces of circumstantial evidence that at first make very little sense. True to Green's style, she calls up and explains each motivation, each piece of evidence with mathematical precision until the mystery unravels, and the perpetrator is punished in a most fitting fashion. In That Affair Next Door, Mr. Gryce owes much of his success to the main witness, a woman named Miss Amelia Butterworth, who lives next door to the crime scene. Having read about Green's life and political views at the University of Texas Tarlton Law Library's "Law in Popular Culture" site, I suspect that Miss Butterworth may have been Green's alter ego. The story itself is written in first person with Miss Butterworth narrating.