The Tricky Business in Mai Chau, by Nathan J. Beyerlein, in Ellery Queen's Mystery Magazine, June 2013.
This is a very old-fashioned story, and I mean that in a good way. It takes place in a current setting but it is about a man who solves a crime through shrewd deductions. Moreso, it is narrated by the detective's companion (in this case, client) who is utterly baffled by the brilliant discoveries. This is aliteraty tradition dating back to Poe, of course, and the first detective stories. Which doesn't make it less fun.
Bertrand Stein lives in Hanoi and he's in a panic. An old college friend has come to visit him and disappeared. Unable to interest the authorities, who figure she is just off sightseeing, he contacts a local American blogger he knows through the Web. Nat Burg is the brilliant amateur detective who solves the case with some very clever thinking and knowledge of the local scene. He is clearly being set up as a series character with tons of eccentricities, mysterious past, and an acerbic tongue. "You asked me to help, not give you a tutorial in basic logic."
I look forward to more adventures of these characters. I do have to point out that when a writer named Nathan Beyerlein writes about a hero named Nat Burg, the name Mary Sue comes leaping to mind.