One mistake will kill a story faster than any other: not following through. Anything that goes into your story has to come to a satisfying conclusion. It’s here that most authors fail, whether they’re just starting out or they are multi-book veterans. This ranges from huge mistakes like failing to wrap up a major plot strand to characters not evolving to bringing in a small mystery clue that never shows up again. When a story doesn’t work for an audience, it’s likely that it comes down to one variation on failing to follow through.

There are no exceptions to this rule. Even if there are, you might as well ignore them. You’re much better off assuming that anything you put in the story is a sacred pact with the audience. You’re promising to follow through, promising that if readers stick around until the end, it will all mean something. When it doesn’t, it violates the readers trust and they turn on you. When the star crossed lovers don’t meet in the end, when the hero doesn’t battle the villain, when a minor character appears in the middle of the book only to disappear and never to be heard from again, it’s a failure that can unravel all that hard work you’ve done on character and setting and plot.

Let’s take a look at this in action. I’ll use some James Cameron films to illustrate. Cameron is arguably the most commercially successful writer/director in film history. He’s had not one, but two films gross more than a billion dollars. To put this in context, there are 15 films that have crossed the billion dollar mark, so it’s a small club. It doesn’t stop there though. 10 of those were sequels, meaning that they already had a built in audience hungry for more. It’s much harder for brand new IP to make it into the billion dollar club. Only two flicks on the list made more than 2 billion each, both of them Cameron’s films, Avatar and Titanic, both NOT sequels but new IP. The next closest film to the 2 billion dollar mark is The Avengers, at a paltry 1.5 billion. Now, of course, just because something made a lot of cash doesn’t mean it is a good story, but when it comes to Cameron I believe that he’s the most commercially successful storyteller in the world for one very specific reason: the man understands follow through like nobody else. If a character starts off on a redemption arc, then by God he will be redeemed. If some unique prop shows up early in the story, then you can bet it will have some important role to play in the film’s final action. Cameron always follows through for his viewers.

Let’s check out a few examples. One of the best ones comes from Aliens. Early in the film soldiers use robotic “loaders” to lift missiles and cargo onto warships. Ripley, the film’s hero, proves she can cut it in the boy’s club of war with brute force manual labor by hopping into one and showing marine Sergeant Apone her skillful use of the heavy machine. In the film’s climactic scene, we see the terrifying mother alien hunting the young survivor Newt, an eight-year-old girl. The door opens and we see Ripley, surrounded by light, strapped into the loader, and ready to do battle. The scene culminates with one of the fims’s best one-liners, “Get away from her you bitch.” In the hands of an inferior writer, the original cargo-bay scene would be the last we saw of the loader. It would have served the singular purpose of demonstrating the hero’s skill and self-determination. It would have only marginally satisfied sci-fi viewers, as we got a glimpse of some cool futuristic tech. Nevertheless, in the end, it would have left audiences feeling unsatisfied at a deeper level that they couldn’t explain. Everything must serve multiple purposes in great stories. It isn’t enough to throw in some cool exoskeletal loaders and a masterful action movie one-liner to top off the scene, the loaders must return for something greater. That’s follow through. And speaking of the little girl, that demonstrates follow through as well. The girl is introduced early in the film. She’s terrified, filthy, and living in the air ducts. She won’t speak. It takes Ripley, a mother figure to slowly break through the girl’s shell and reach her. Again, in an inferior writer’s hands they would have let it drop at that. Ripley is not just a warrior, she’s also a mother figure. She’s layered. She has depth. By deciding to bring Newt back at the end of the film and putting her in mortal danger, now we really get to see a mother defend her child. This is Ripley, the ultimate warrior mom, defending her child at all costs. This is how you deliver for an audience. Nothing in a great story is superfluous or incidental. It always has to serve a greater purpose. That’s why a candle isn’t just a candle in a murder mystery, it’s the weapon used to kill our victim.

My old friend Simon came up with a good analogy. Timmy and Johnny go into the woods and they brought a gun and…nothing happened. It can’t go like that. If they bring that gun, then something bad needs to happen. Most importantly, it has to happen with that gun. It can’t happen with a stick or a stone instead. Well, it can happen with a stick or a stone, but only in a mystery, where the gun looks like the murder weapon the whole time, only for us to find out it was used as a clever ruse by Timmy. Notice how the gun plays a central role even in that scenario. When authors introduce something then don’t follow through, it’s the equivalent of Tommy and Johnny going into the woods with that gun only to have a picnic and happily return home. Not much of a story, is it?

If you think about Cameron films, several more examples stand out. Think of the priceless necklace in Titanic, the Heart of the Ocean, a blue diamond. The search for the necklace kicks off the story, sending a group of adventurers out to sea in hopes of finding the priceless object. This acts as a framing narrative, as the film’s protagonist Rose, who once owned it, relives her life. It shows up again as we hear her story. Her husband, one of the film’s villains, a man of wealth and power, owns it. It symbolizes his ability to get almost anything done with his money. It symbolizes the divide between rich and poor, as he and Rose end up in privileged cabins, while the poor ride like cattle in “steerage.” In the end, we find Rose has kept the necklace all along. It was never lost. In the final moments of the story, she drops it into the sea, symbolizing her shrugging off the constricted life of the rich and powerful coupled with her awakening into a life of true power and freedom and creativity.

Don’t make the mistake of thinking this principle is just limited to objects. It permeates every aspect of story-telling. If you introduce a character, then he has to do something. If you introduce a theme, then it can’t just evaporate mid-stream. Imagine if the woman in Titanic learned nothing from her relationship with the young artist? What would happen if her relationship was nothing but a meaningless fling and she stayed with her rich husband? The story would have no meaning. By introducing the brash young artist, not constrained by societal limitations, who opens her up to life’s possibilities, it’s a direct invitation to the protagonist. She has to react to it. If she doesn’t make a choice arising from that very conflict, then the writer fails. She either has to choose to throw it all away and live the unenlightened life (a tragedy), or embrace the change and become her true self (the inspiring ending). There really is no other choice. If the final internal struggle revolves around some other conflict, it doesn’t work. That’s a conflict that belongs in a different story. The reason is because of the set-up. Cameron sets up the character from the beginning as rich but unhappy, searching for deeper meaning. The artist offers the possibility of finding it. The arc from there is quite simple. It can only end one of two ways. The set-up is both the great enabler and great limiter of a story. A great writer embraces the limitation. An amateur chafes at it. The professional follows through and delivers. And he manages to do it in a unique way, even though it can only go in those two directions. That in-between section is where the story’s originality comes in. Don’t try to be original by breaking the character arc. It won’t work. You’ll only shoot yourself in the foot and make your audiences hate it because you cheated them. You didn’t answer their burning questions. You left them dangling. You wasted their time. Revel in the limitations your set-ups bring. After all, you chose that limitation in the first place. You wanted to say something about life and love and freedom. You chose to tell this particular story. So, tell it. Accomplish that and you’ll find your audience. But, if you set up something and let it fall apart down the stretch, you’ll only earn yourself some one and two star reviews on Amazon. And you’ll deserve it.