Building a Mystery

I have a love/hate relationship with Agatha Christie. She was the first adult mystery writer I became hooked on, after going through the Alfred Hitchcock and the Three Investigators series and the Trixie Belden series in elementary school (don’t even ask about Nancy Drew or the Hardy Boys. Do. Not. Ask.) After I overcame the outrage and disgust of Roger Ackroyd, I became a huge Miss Marple fan. Then I read all the Hercule Poirot books. Then everything else. Where does the hate come in? Miss Christie had this annoying habit – in most of her books, anyway – of keeping clues very close to the chest. Poirot or Miss Marple would come to investigate something, or Miss Marple was invited to an estate party out in the country (and I loved those estate parties. Except for everyone getting killed off, they sounded great!). People would start dying. Then at the end of the book, the detective would announce all the info she had gathered on the guests, and who was the murderer. This info was generally not shared with Dear Reader, meaning Dear Reader did not have the same opportunity to solve the mystery that the detective did.

Somewhere down the line, someone realized that readers want an equal shot at figuring out Who Dunnit, so this formula was changed. Readers took their spot over the detective’s (and this includes amateur as well as professional) shoulder and were privy to everything the detective learned. This turned the act of reading into a game… could the reader figure out Who Dunnit before the detective?

I must prefer this style of mystery than the former. However, with nearly forty years of mystery reading behind me, I am getting pretty tough to fool. Generally there’s a line that the writer tries to slip in casually (in a recent book, it was something about a man thinking a teenage girl was older) that sets off alarm bells for me, and most of the time, I’m right. I was right about the husband gaslighting the wife (He had a strong, clear motive that the writer tried to casually drop in.). I was right about the ex-boyfriend (He had no motive but I could figure out what happened in the back story). I was right about the missing girl’s father (He was the one with the eye for very young girls). I was right about the man pretending to be his cousin (He was an already established creep, and the writer took pains at keeping two characters apart until the big reveal).

I like being right, but at the same time, it worries me as a writer. If I can unravel these clues so easily, are the readers of my mystery going to be able to do the same thing? What is the balance between being fair to the reader and giving her enough information to solve the mystery, and going overboard and basically giving away the store? What's the secret to fooling the reader?

If you’re a mystery reader and can recommend books that left you stumped, please do so in the comments!