Welcome to the big mess that is modern intellectual property laws. Do not believe me? Take a look at the following as an example:
These laws were not any easier to understand almost 60 years ago when this book was first published. A group of publishers and authors came to Nero Wolfe for a consultation. Somebody devised a good blackmailing scheme involving bestselling books. Basically as soon as a book reaches bestselling status a person - different every time - comes out and claims he/she submitted the book for publication before the published book was written, but it was rejected and the manuscript was never returned. The said manuscript suddenly and unsuspectingly appears in publication group's archives. An invitation to court follows with the charge of plagiarism.
It took me awhile to explain the clever but illegal money making scheme, but it is actually quite simple. The investigation however was nothing but. It involved quite a few dead bodies, plot twists and one of the most complicated mysteries of the series. Both detectives also managed to get an egg on their faces and thus it became personal for them especially Nero Wolfe who has a very high self-esteem.
So in conclusion in addition to the usual great interaction between the characters this novel also has a very complicated mystery which I mentioned above as an additional bonus.