The most important thing in a mystery story is that when everything is resolved, some clues as to why the protagonist sorted it out are given. The real masters (Agatha Christie comes to mind but I draw the line at mistresses!) leave some clues in the story that the reader could pick up, but usually in a way that the reader is most unlikely to pick them up. The aim should be to tidy up the story, but a further objective might be to reward the perceptive reader. Perhaps the hope is the reader will think how clever the protagonist was, but of course having the writer directing gives the protagonist something of an advantage. There are different sorts of clues, but the one I am picking on here are the lies. The point of a mystery story, of course, is that the guilty parties may always lie, and catching out the lies is part of detection, although that method is complicated by those innocent of the specific crime also lying to cover up something else. The problem comes when the author accidentally makes some just plain mistakes.
A number of stories have the elements of mystery about them, even if they are not really mysteries, and a book that led me to write this blog is Frank Luna’s Red Storm. It is nominally a SciFi thriller set on Mars, but it has the elements of a mystery embedded in it. There were a number of statements that were incorrect; some could have been intended as critical clues, and if so they were really good ones, but their value was reduced for me through the odd mistake. I mentioned this in a review, and maybe I was a little hard on Frank because the “facts” about Mars change. Maybe in another couple of decades someone will do the same for my Mars novels. In this sense, if you read Kim Stanley Robinson’s Mars books, there is quite a bit there that is almost certainly wrong, BUT these books should not be read as what Mars is like, but rather an archive of what Mars was believed in the early 1990s to be like. Since Frank’s errors were similar, perhaps he was merely out of date.
Back to the issue of clues: how do you introduce deliberate clues to identify the guilty? Here are my views. One thing that must not be done is to present it with a flag, effectively saying, “Hey reader, big clue here!” On the other hand, if it is so obscure that nobody could possibly see it, it is really a waste of time. Good clues are to test the reader, not to demonstrate some sort of superiority on the part of the author. One guideline is not to tell the clue if you can help it – try to make the guilty party say it. Failing that, get someone else to say that (s)he had heard that . . and try to say who originated it, unless that is part of the further puzzle. Try to avoid showing lies as observations, and try not to present told descriptions that are untrue.
There is one further point. The author, particularly in scifi, may wish to introduce something that may or may not be true, but is believed by most not to be. How do you introduce that? In my Red Gold, I put forward a different theory of the origin of the Martian atmosphere. The reason was, the story is about fraud, and I needed a totally unexpected discovery to expose it. This was introduced as a discovery, and to elaborate, I put a more complete discussion as an appendix, so as to give those interested something deeper to consider (I actually believe the discovery will be made, so up to a point I have falsified my own plot!).
Anybody else have any ideas on how to do this? Finally, since I have picked on a specific author, I should add that I enjoyed the book, and if you like reading Scifi on Mars, Red Storm is well worth considering.