When I’m wandering my way through a plot, I’ve written a few characters for whom the arc is just them learning a series of secrets that eventually leads them to foil the baddies. It’s pretty much just a plot-driven conflict disguised as a mystery, and it’s not doing either one of those things very well.
The best insight I’ve had into solving this problem came when I looked at the villains first. What I had was Bad Guy trying to get away with something delicately couched as a secret plan. If it wasn’t a secret, the heroes and the entire world itself would have no trouble eyeballing that plan and raising a stink about it.
My villains were weaksauce. What they were doing relied entirely on the rest of the human race just not noticing the heist. Sometimes the vehicle for this was that my villain was actually pretty influential, but was tackling this one alone for the glory. Other times it was the opposite—Bad Guy is essentially just a nobody with a secret to turn the world on its head.
Consider a different look at the problem of the villainous trail. When my hero, we shall call her Good Gal, is finding clues laying around, it calls into question what kind of operation Bad Guy is running here. If Good Gal finds this garbage, why not someone else? The answer might help you weave the details in your own trail mystery in a believable way, but you can’t get very far by ignoring the question. Like if this is Bad Guy’s master plan and life’s work, what in the world would possess him to be this careless about the trail?
The issue as it relates to Good Gal is that the plot for this story can be summarized by “someone gets information that Bad Guy wishes they hadn’t”. Not super compelling, and worse, Good Gal could literally be anyone. She could be the least engaging character in the Milky Way and a the story would be fundamentally unchanged.
It was now time to look back at Good Gal. I was addressing some of the believability issues I had about this villain of mine, but Good Gal was still lacking. In a disgusting case of her being possessed by the plot itself, she was doing whatever had to be done to make sure Bad Guy got caught. She was moving from one thing to the next, the clues themselves nominally markers for progress, but without any development on her end. She perhaps had a moment of change when she encountered the first clue and the story begins, but after that, she was not forced to cross thresholds that committed her to seeing it through.
The most meaningful thing you can make a character suffer as plot progression markers fly by is to come up with reasons why the Good Gal can’t just turn back. “I’m so close to solving this that I can’t turn back!” is a pretty unconvincing motivation all by itself.
Markers of progress need to cost something, either personally or against the greater debt implied by failure. This doesn’t have to be earth shattering, just something that stops the character from going back to the way it was before. Learning something isn’t often a strong enough call to action to do that. Most of us could learn something awful about the world and retire to an island mansion and never think about the rest of the messed up world ever again.
It could be that all we need is Good Girl in Act II messing up a friendship with someone that she respects. She could miss her rent in the chaos of the chase, and now she’s got nowhere to crash when she really needs it. Someone could die, in an extreme case. Perhaps inaction is to blame, and she loses the one chance she was counting on to have some closure with her past. Literally anything is going to be better than nothing.
No personal stakes means the story isn’t drawing you forward with each event, and if I’m missing that component, then my engagement with the character is going to grow thin.
Learning things doesn’t automatically make Good Girl a deeper character, but if such a thing transforms her outlook or alters the motivation she has, I’ll have done a much better job writing her character.