BILL PRONZINI “Gunpowder Alley.” John Quincannon & Sabina Carpenter, 1890s San Francisco. First published in Ellery Queen’s Mystery Magazine, August 2012. Reprinted in The Best American Mystery Stories, edited by Otto Penzler & Lisa Scottoline (Houghton Mifflin, softcover, 2013). Combined with one or two other stories to form The Dangerous Ladies Affair, by Marica Muller and Bill Pronzini (Tor, hardcover, 2017).

   One time Secret Service Agent John Quincannon and his partner, a former Pinkerton detective named Sabina Carpenter, have joined forces to establish their own agency, Carpenter & Quincannon: Professional Detective Services, and have had many cases together, mostly individually but on occasion working together. This is a purely professional, as much as Quincannon would wish otherwise. I have not read many of the stories that come after this one, so I do not know whether they ever do get together romantically. Will he? Will she? I cannot tell you.

   Quincannon works on this case pretty much solo, but when he finds himself stumped, he always has Sabina to tell his woes to, and not too incidentally, obtain useful advice.

   Dead by a fatal gunshot wound is a blackmailer Quincannon had been hired to follow. He is found in the back room and living quarters of the his tobacco shop on a dingy street called Gunpowder Alley. What stumps Quincannon is that the dead man, along with the gun that did the deed, is in a room that can be entered only through two locked doors, with no access through the barred windows.

   It is quite a puzzle, and it is no wonder that Quincannon is totally stumped, but after a little of Sabina’s support, he at length figures out how the killing was done. The solution is very meticulously worked up – this is one of those mysteries that once the explanation is given, you the reader (unless you are more clever than I) knocks him or herself on the side of the head and says “Duh.”

   Adding to the pleasure of reading this story is the equally meticulously described setting: 1890s San Francisco, where glitter and dark dismal streets and alleys exist almost side by side.