Every plotted novel needs an antagonist — someone to make the hero’s struggle difficult. In a few cases, the antagonist might be the raw forces of nature rather than a human, as in some of the stories of Jack London. Or it might be the dark side of the hero’s own personality, as in The Strange Case of Dr. Jekyll & Mr. Hyde. But most often it will be a human villain of one sort or another.
The temptation, for the aspiring writer, is to have the villain throw into the hero’s path whatever dangers and obstacles are necessary to keep the plot bubbling. When the story starts to sag, have the villain do something nasty! That’s a reasonable approach, but it has to be handled with care. Here’s why:
The villain, whoever he is (and we’ll assume it’s a guy, though female villains can be just as devilish as their male counterparts), doesn’t do things merely in order to make the hero’s life difficult. Nor in order to make the author’s job easier. In his own head, the villain is the hero of the story! The villain has a goal, a human motivation, and will only do things that make sense to him at the time. He may misjudge and do things that fail to advance his twisted agenda, but if his only agenda is “make that damned hero suffer!”, the writer has failed to create a realistic character.
Not all writers care about crafting realistic characters, of course. Arguably, they should care.
While we’re on the subject, fictional villains have a silly habit of wanting to explain themselves. At the climax of the story, the villain has the hero flat on his or her back, is holding the gun, and has obviously won the contest. And strange as it must seem, rather than simply shooting the hero in the head and walking away in smug satisfaction, the villain always pauses to boast. There are two reasons for this ridiculous scene. First, the writer needs the villain to explain to the reader exactly how he has done all the nasty things he has done. Second and even more important, the villain’s sudden attack of Chatty Cathy gives the hero just barely time to grab the gun and shoot the villain, thereby turning the tables and turning disaster into triumph. It’s a happy ending!
I’m pretty sure there were a lot of chatty villains in the James Bond movies, but it didn’t end there. I’ve seen the same discouraging flaw in the generally terrific crime novels of Michael Connelly. Real bad guys do not act like this. At least, most of them don’t. Sure, a few of them have that kind of big ego, but they don’t all.
Do not let your villain stop to explain. Come up with some other plot twist.
It’s a convention of the modern crime novel, and to some extent of all plotted fiction, that at the climax of the story the hero has to go up against the villain single-handed. And preferably without adequate weapons. This is because there’s less tension if the hero has allies or a grenade launcher. The reader wants the hero’s victory to be as admirable as possible, and coming from behind is more admirable than strolling to victory in a contest where the villain was obviously outmatched.
Again, Michael Connelly: In a couple of his Harry Bosch novels, the reasons for police backup not being called were thin and unconvincing. Connelly needed Bosch to go one-on-one against the killer, and Bosch is a cop, so there had to be some contrived way to keep him from calling for backup. You know, a busted radio. Whatever.
Making the final confrontation believable is hard work.