The are times, as a writer, when you want to surprise your readers or give them a puzzle to solve. That’s clearly a major part of a murder mystery, of course, but you do it in other stories as well.

Anyone who has ever aspired to write mysteries has read about the rule of not cheating the reader. Cheating is when you completely withhold information required to solve the mystery. All information has to be available to the reader. It is okay to obfuscate it, but leaving it out entirely is a no-no.

The classic example of the wrong way is describing your detective, perhaps despondent, looking down at his feet and seeing something. He bends down, picks the something up, and then smiles as he slips it in his pocket and the narration informs the reader that this thing is the vital clue that makes everything fall into place. But the writer doesn’t tell the reader what the something is.

The proper way to hide a clue is in plain sight. I remember one mystery once had three characters talking about something, when the father comments on his daughter’s dress the night before, saying it was a nice shade of green. One of the other characters tells him the dress was red. The father goes, “Oh, well, I guess it is.” The way the scene is written it seems that the father is simply not very attentive or perhaps distracted. Later in the story, it is revealed that he suffers from a form of color blindness, and that is an important clue about an aspect of one of the murders.

I’m currently wrestling with a version of this issue in a non-mystery. My current novel in progress (which is a light fantasy) includes a mysterious masked person who has appeared a couple of times, thwarting an assassination attempt directed at a princess, preventing a sorceress from getting some information, and a few other things. In the very first scene his mask is commented upon, and an explanation for why he is hiding his identity is provided.

So I wrote a scene last week where he confronts the man behind the assassination plot. I realized midway through that I could make the scene far more creepy than it already is, but I think I would be cheating if I did.

It occured to me that I could have the masked man reveal his face to the conspirator just before killing him, and show the conspirator reacting with shock at the identity… But withholding the identity from the reader. Certainly movies, television shows, and comics have used that particular cliche many times, so one could argue it’s acceptable. But even then, usually the reaction of the character to the revealed face provides an extra clue about some aspect of the story other than the identity of the mysterious person.

Besides thinking the technique is overused in those media, I’m not sure it makes any sense for the masked man to do it. The most obvious reason, “I want you to know who defeated you,” simply doesn’t apply to this character and his relationship to the conspirators. Besides being out of character, it would also be a bit too self-consciously coy. By this point the theoretical reader is either curious about the identity of the masked man or already has a theory. A melodramatic nonrevealing reveal is more likely to annoy than fascinate, I think.

And this little mystery isn’t the main plot. If I’ve done the rest of my job correctly, what I hope the reader is more worried about by this point in the book is: whether one grief-stricken character will go through with killing some innocents to bring another character back from the dead, whether one protagonist will clear his name and rescue his nieces, whether other characters will prevent a war, and whether one villain will be redeemed.

My mystery man is important to the plot, and why he’s attempting to act incognito is totally in keeping with his personality while moving the plot along, but it isn’t the main concern.

A puzzle as a subplot can be fun for the reader. Keeping the reader guessing about a few things without annoying them is a tricky balancing act. You want to provide enough information so that your reader can guess, while leaving some doubt. You want the reader to feel almost as if he is your accomplice–as if both of you are exploring this thing together.

Doing something such as having the detective find something which you blatantly label a clue which you withhold from the reader, or the unmasking without showing the reader, is the equivalent of a stage magician declaring, “Ha! Ha! I know something you don’t know! I know something you don’t know!”

And that’s just annoying beyond belief!