The Mandarin Mystery (1936) is an Ellery Queen story, which means that the fictional Queen and his father, a police inspector, have to figure out how one, then two, murders have been committed – and why.
It’s not bad, but the storytelling is brittle, meaning the suspects are basically from the usual herd of 1930s suspects, and the idea that a postal stamp worth $50,000 in the money of the period would be carried with virtually no safeguards is a plot hole that may have been believable in the thirties, but surely isn’t now.
The Queen character is played with some verve, but in the end this is a minor failure of a story. I couldn’t figure out why I should care, and if I can’t figure it out for myself, I can’t figure it out for you, either.