Characters, I’m certain it’s characters because they drive the story. The character makes the plot because it’s not about “what happens to them” it’s about “the journey the character makes and what changes about them”. I don’t know if that makes sense.

Like, ok I might start with something that seems like “plot” first e.g. the ConArtist!Belle and Mark!Gold AU fic that basically popped into my head due to my love of Leverage and Hustle. I just sort of wondered about a crew like that hearing Gold’s “bad reputation” and going to take him down but Belle realizes he’s not the man she thought, and she was glad and very much in love, but Gold thinks she’s someone she’s not.

So immediately it turns back to the characters. Without them there is no story. I mean even a “case of the week” show like Leverage still springs from the characters. The cons are secondary to the subplot of something a character is going through, or the character works it out through the con. For example I mean Parker in Leverage had an amazing character journey. She went from being completely closed off and stabbing people with forks because she didn’t know how to talk with them. To showing her compassionate heart, to falling in love and building a family with the team, making friends and well she got better at being a con artist and able to perform a role. I love Parker.

Anyway, characters create the plot. I might have a “situation” but if there’s no character journey, if nothing happens to change life for the characters, then there’s no plot. I’ve written series fics before and after the first couple, I don’t need to “think of a plot” because the characters have it covered. Based on what happened to them in the first couple of ‘episodes’ they now are telling me what needs to happen next.

TLDR: Characters definitely.