Post History
The only way I can think of solving this puzzle is if the protagonist was never really interested in foiling a plot in the first place, but gets their revenge, and from their point of view justice ...
Answer
#4: Attribution notice removed
Source: https://writers.stackexchange.com/a/32713 License name: CC BY-SA 3.0 License URL: https://creativecommons.org/licenses/by-sa/3.0/
#3: Attribution notice added
Source: https://writers.stackexchange.com/a/32713 License name: CC BY-SA 3.0 License URL: https://creativecommons.org/licenses/by-sa/3.0/
#2: Initial revision
The only way I can think of solving this puzzle is if the protagonist was **never** really interested in foiling a plot in the first place, but gets their revenge, and from their point of view justice gets done against those that wronged them, and they "won" somehow (are made whole or richer) without actually uncovering the **motivations** of the villain. I don't have good examples, most producers/publishers would feel the same as your friend; there is a good reason nearly all books and movies have happy endings. But the first "Taken" movie might nearly qualify: A secret agent's daughter is kidnapped while on vacation overseas, to be sold as a sex slave. His only goal is to rescue his daughter by killing a few dozen people, which he does. It is an "inventive murder" film, all covert battle action by our hero, motivated (for the audience) by regular scenes of frightening brutality of the villains treating girls like disposable meat. In the end the secret agent doesn't take down the whole foreign sex trade (implausible anyway, there are millions of girls in sexual slavery), he follows a trail to rescue his daughter and finally does, just before she is to be raped by a 'customer' (also killed). Then the movie is over; our secret agent "wins" even though he leaves behind rampant injustice and the kidnapping will continue. (and sets up the revenge sequel, since he killed the son of a powerful slaver.) He got what he wanted, his daughter back unraped, and just about everybody directly involved killed. The mystery doesn't have to be solved if your protagonist doesn't care about it, give your protagonist a compelling smaller goal to achieve. However, you cannot have it both ways, IMO that will not be published. By 'both ways' I mean you cannot focus on this mystery throughout the story, and investigating this mystery, and people dying trying to discover the answer, and then not reveal it! If what is driving readers to turn pages is wanting to know how the riddle is resolved, you must resolve it. That said, you **can** have a plot-driving riddle the protagonist is **not** trying to solve. Instead, some fallout of this plot is threatening the protagonist or those he loves, and **his** goal is to eliminate the threat, not necessarily thwart the villain. Or his goal is to prevent one small part of the villain's goal. So you can focus on the protagonist's smaller goal and have a larger plot peripheral to it, or that incidentally caused his dilemma, moving actors around offstage to create obstacles in the protagonist's path. But if the villain's whole plot is the focus of the book throughout, if you are describing mysteries that really have nothing to do with the protagonist's dilemma or goal, then you must resolve the larger plot.