Professor Plum, in the Library, with the Lead Pipe

We’re all familiar with that title reference, yes? Even if you never played as a kid (or a semi-drunken college student), you’ve probably seen or heard about it. Clue is the classic mystery game, where you have to determine the murder weapon, the scene of the crime, and (of course) the killer.

A game of Clue isn’t much of a mystery, however. It’s more of a puzzle you just need to solve though the process of elimination. We never find out why the good professor felt the need to cave in Mr. Boddy’s skull. Was it an act of revenge, long-overdue justice, or just a heated argument that boiled over into violence? Similarly, Plum never offers any sort of defense or alibi. He just ends up being the only person who can’t account for his location at the time of the murder, so we cart him off to life behind bars.

Motives and alibis are what really separate a mystery from a puzzle. They’re the human element that makes things either a little more complicated or a lot more difficult, depending on your point of view.

The motive is why someone does what they do-- the personal reasons behind the action. Why does the Monster (sometimes called Adam) kill Victor Frankenstein’s bride-to-be? Why does Lando betray Han? Why does Romeo kill Tybalt?

If you really think about it, though, most characterization comes down to motives. Knowing why someone’s doing something—anything, not just criminal acts-- tells you a bit about them. We learn a lot about the good Doctor Jones simply because of his desire to go looking for the Ark of the Covenant, but also because he mocks the ideas behind the fabled treasure. You can ask these sort of questions about most great characters. Why is it so important to Atticus Finch that Tom Robinson receive a fair trial? Why is young Edmond Dantes so determined to escape from prison? Why does Dot keep hitting Yakko with that hammer when he’s not looking?

You can even look at motives in a negative light to help define characters. Not why characters do something, but why didn’t they do something else? Sometimes people make difficult, troublesome decisions that are going to cause problems, and that can tell your audience something about them as well. Why won’t Nick Andros abandon Tom Cullen (M-O-O-N spells Tom) so he can travel faster to Denver? Why doesn’t Louis turn Rick over to the Nazis for shooting Major Strasse? Why won’t Prince Hal acknowledge his friendship with Falstaff?

Motives don’t need to be big, elaborate things, mind you. “Bob doesn’t want to get beaten up,” is a perfectly acceptable motive. So is “Beatrice wants to sleep with Larry” or “Pinky is hungry.” Not everyone has to be hiding a dark secret, keeping themselves out of the electric chair, or protecting the Holy Grail.

The real failure comes when characters do things not for their motives but for the writer’s. If you ever look at a character action and the reasoning behind it is “because X needs to do Y,” that’s false motivation. The writer is looking forward in the story rather than back at character development. And character development is where all your motivation is going to come from.

Now, in mystery stories, the alibi often walks right alongside the motive. Simply put, the alibi is the reason you couldn’t’ve done the crime, even if you had a reason to. It’s contradictory evidence. We know Miss Scarlet was in the greenhouse and Colonel Mustard can’t lift anything over his head since the war, so they’re off the hook for Boddy’s murder. We may find out later Scarlet was in the bedroom with Mrs. White and Mustard’s medical records were faked, but that just makes the mystery a little juicer.

In fact, alibis make most stories a little more tasty, because keeping something hidden makes other characters (and the audience) think twice. It’s when you want to deceive your audience and keep a little something from them to improve the story. Most romances wouldn’t be as interesting if at least one of the two parties involved wasn’t completely denying an attraction. Stu Redman must die in that ravine, because none of his friends ever see him again. And there’s no way those robots can do anything wrong, because the Three Laws will keep them on the straight-and-narrow path every time, right?

Note that in many of these examples, the writer isn’t even lying to the audience. If the reader chooses to interpret things a certain way (a wrong way), that’s hardly our fault is it? Well, okay, it is, but we’re doing it for a good reason. The key thing is, none of these alibis are cheats. There’s a good reason none of Stu’s friends ever see him again. The robots really are following the Three Laws (as best as their little positronic brains can, anyway). And, come on, who’s really going to admit they’re attracted to a guy like Chuck, right?

So, even if crime doesn’t pay, you can still get something useful out of it. If your characters always have honest motives, they’ll be real. If they always have compelling alibis, they’ll be interesting.

Next week, since it’s been brought it up once or thrice, we’re going to talk about the rules. To be more specific, we’re going to talk about being the exception to the rule, because that’s what most folks are more interested in.

Until then, get yourself motivated and go write.