Selena Mead, while in Europe, falls in love with and marries an up-and-coming reporter. When she learns that her husband had been killed, she also learns that he had for many years been a top operative of Section Q. Now she decides to find and bring to justice her husband's killer, becoming an agent herself.
Note: This book is actually a "fixup" of several short stories originally published in This Week and Ellery Queen Mystery Magazine, edited to create a complete novel. While the stories contained are some from before the second book or just after it, this fixup itself came out several years later but the story precedes the second book. The original stories from which the book was likely constructed were:
Note: see the opening comments of the Novella section for more information.