Mysteries and thrillers are my favorite reading material. I am still learning how to effectively write for this genre, but I would like to share some of what I have learned with you.

When writing a mystery, do not neglect to tell a major bit of info that could allow your reader to figure out the mystery on their own. If you still manage to fool them, you should have a loyal fan. If the reader can’t figure it out because you withheld a vital piece of info, chances are he will never pick up another one of your books.

Always bring the killer into the story early on. You’re bound to have read a mystery or watched a movie where the killer turns out to be someone whom you’ve not been introduced to yet, like the victim's ex-daughter-in-law. It was never even mentioned or hinted at the the victim's son had been married, much less divorced. I’m sure you would feel cheated. You don’t want your readers to feel that way.

Mystery and suspense novels are great when the ‘unreliable narrator’ is the one who tells the story. He or she can only tell what he sees, what he experiences, what he is told, but he doesn’t always really see what the true events are. Just be sure it is the narrator who is unreliable and not you, the writer. "The Murder of Roger Ackroyd", by Agatha Christie, is a great example of this type of story.

In the past, novels could have a slow beginning. If you have ever read anything by Mark Twain, Charles Dickens, or Jane Austen (there are several others, as well) you know what I mean by slow beginnings. Granted, none of them exactly wrote mystery/thrillers, but exciting things did happen in their stories. Parts of them are extremely tedious and boring, though those parts are crucial to the times in which the stories took place. In modern times, though, I believe they would have to learn to work in those details in a way that was not as dull.

Your story needs to have an opening that will hold your reader’s attention. It should not be slow, boring and full of details that you think the reader needs to know. If the details need to be known that badly, they can be revealed through dialogue, flashbacks or other events throughout the story. Nor is a lot of history that happens before the action needed. What your reader needs at the beginning is a reason to continue reading your work of fiction.

Clues that are able to solve the case, but are not readily obvious, need to be left lying about throughout your entire story. When the reader finishes, he should be able to look back and think, “I should have seen that. It was so obvious.”

Don’t forget - everything you write must have some connection to your story. Don’t go around creating intricate twists in your plot that have absolutely nothing to do with the story. The events either need to move your story forward or build on your characters. Just as every character needs to have a connection to your story, not just be there as filler, every happening needs to have a connection with you plot.

How do you make sure each happening has a connection with your plot? Take apart each event, no matter how insignificant it may seem at first, and plan it out. Say that the snobby cheerleader Andrea sticks her foot out and trips the class geek, Charlene, in the school cafeteria. Everyone thinks it is hilarious and cracks up laughing. Charlene is humiliated and runs off crying. Her few friends try to follow and comfort her, but she only tells them to go away. She bursts out the back door of the school and takes off walking, planning to walk for the rest of the lunch hour and then return to class. She sees a kitten that has been trapped by a homemade trap near the park. She is a great animal lover, so she immediately runs over to free the kitten. The killer, hiding behind some trees watching the trap he has prepared, sneaks up behind Charlene, chloroforms her and carries her off to his car. Victim #3 is snagged.

If you plan out each event in your story like this, you shouldn’t come up with anything that isn’t tightly woven into your plot. There should be a reason for each thing that happens.

The ending of your novel needs to be satisfying and not a disappointment. I know that I have read both books and short stories that have kept me on the edge of my seat, so wrapped up in anticipation of what was going to happen that my housework was seriously neglected. Then I reached an ending so disappointing it made me want to throw the book or magazine across the room. I sure don’t plan on reading anything else those particular authors wrote.

One way to avoid this is to write your ending first, even several endings so you can choose the one that satisfies most. Then work your way towards that ending. That doesn’t mean you can’t change it. It is never written in stone until it is published.