Originally published in 1937, this fifth and final "Sergeant Studer" novel (following Thumbprint, Fever, In Matto's Realm and The Chinaman),finds the grumpy Swiss ex-detective in Schwarzenstein, presiding over the wedding of his daughter to a nice but somewhat cautious junior policeman. Alas, as is so often the case in mysteries from the "classic" era, a murder takes place on the grounds of Studer's hotel (which happens to be owned by his long-ago sweetheart) just as he happens to be there. This compels him to send the wife and newly-married daughter home while he and the new son-in-law poke their noses into the matter. The initial clues point to an obvious suspect, but the wily Studer can't be fooled by flimsy circumstantial evidence, and starts investigating.
Over the course of the next few days, several other guests arrive at the hotel, and another corpse is produced. Like the others in the Studer series, it's all rather old-fashioned, complete with concealed doors, skulking around at night and a grand finale gathering all the players into a room to unmask the true criminal. And as in the other books, the ins and outs of the case get rather complicated, not to mention tangled up in historical events unlikely to be familiar to most readers. Finally, as in the other books, much is made of the use of formal vs. informal German vs. dialect in various encounters, but these shifts have to be directly explained in the text, which is pretty clunky.
On the whole, the story isn't particularly engaging, and is of limited appeal. Those who've read the other Studer novels, or have some particular interest in Swiss crime novels, or in "golden age" crime novels in general may find it engaging, but others probably not.