In which Henry solves the murder of Mario Gonzalo’s sister.

Few of the Black Widower stories deserve the adjective “chilling,” but this one does, and in spades. Black Widower stories rarely involve physical violence of any kind, let alone murder, and usually when there is mayhem, we tend to be fairly far removed from it—it happens to a friend of a friend of a friend. Here, however, the sister of the mostly vividly realized Black Widower is found to have met a violent and unpleasant fate, and the identity of the murderer leaves a bad, sorry taste in the mouth. This is an excellent story, one of the very best of all the Black Widower series. I'm frankly rather astonished that it didn’t get into The Best Mysteries of Isaac Asimov.