Nero Wolfe is lazy. He only works when his bank account strongly demands it. At the beginning of the book he has enough money not to bother with any cases or clients for a while. When a young Yugoslavian woman shows up asking the detective to help her compatriot and friend with the trouble over accusations of a theft, Nero Wolfe refuses right away without bothering to listen to her pleas. The woman drops a bomb - literally speaking - which left both him and Archie Goodwin speechless (as well as yours truly when I read it the first time). Nero Wolfe has to start the investigation which became personal for him and a little later for Archie Goodwin as well.
My standard disclaimer about practically any Nero Wolfe novel applies here. The banter between characters as well as Archie Goodwin's witty remarks are priceless. These by themselves would make up for a good book. This one has a fairly complicated mystery as well which kept the great detective and his sidekick baffled until practically the very end. Speaking of the latter, Archie Goodwin shows himself a good detective on his own right, not on Nero Wolfe level, but quite competent nonetheless. For the additional bonus, there was an action scene involving Nero Wolfe whose lifestyle usually insures he does not have any.
The rating is four stars for a good book which is on the level with the quality for the whole series.
This review is a copy/paste of my LeafMarks one: https://www.leafmarks.com/lm/#/users/10968/books/144695/review