by Barbara D'Amato
You're writing a crime novel. You've worked out a surprise ending. You want it to make sense when the reader arrives at the end, but not to be so obvious that readers go "Aw--I saw that coming." Since readers differ in their ability to deduce, as well as their desire to deduce--like the reader who says, "I try not to guess the ending; that ruins the surprise," -- how far do you go in planting clues?
You might feel good about producing a book that in your opinion was obvious enough so that ten per cent of the readers can deduce, not guess, whodunnit and ninety percent can't. You would delight in the rest being surprised, but telling themselves they had every reason to know the guilty party.
Agatha Christie said that she didn't understand why people didn't guess her endings early on, they seemed so obvious to her. And indeed most of her Marples and Poirots really play fair with the reader. I suspect that she knew perfectly well she was hitting a golden mean of obfuscation.
Where this is really critical, of course, is the traditional puzzle mystery.
Ellery Queen issued a challenge to the reader. Somewhere near the end of the novel was a boxed announcement, saying that the reader now had all the clues that Ellery Queen had seen and that only one solution was possible. I believe his first mystery carrying this challenge was THE ROMAN HAT MYSTERY, but it became a feature in several novels after that. The challenge boxes were inserted at the proper place in the manuscript after typesetting. I would imagine that the writers, Manfred B. Lee and Frederic Dannay, would have been happy if ten or fifteen percent of their readers got it. Then the rest could exclaim "Of course! I should have seen that."
However, the same balance is important in a private eye novel where there is no assumption that the reader will deduce the ending. The reader may find out the explanation at the same time that the shamus does. Or the thriller. Take something like the double-twist, triple-twist endings of Harlan Coben. They may be astonishing, but they can't be out of left field. They have to be satisfying.
Satisfying, of course, is not the same thing as predictable.
Challenge to the reader. Challenge to the writer.