I just wrote a great dialogue scene between Willa and Saadia. Ah, Saadia. She's not a major character in The Owl Bearer by any means, but she's also a secondary character in Eleven Names, which means I can't just make willy-nilly decisions about her because I have to live with those decisions when I get back to writing EN. I know who Saadia is in EN, but TOB is her distant past, so I had to figure out where she comes from. She's been through three MAJOR revisions since I started working on TOB: from an undercover (male) anthropologist who gets to know Willa while wearing a "field work" body; to the young and oppressed wife of one of Willa's fellow envoys; to an older woman who is herself the envoy and has her own agenda to pursue.
What's interesting is that snippets of dialogue from the first draft of the scene were still usable, even though Saadia is completely different person. For example, there's a bit in which Saadia complains about the restrictions of marriage that became, in this draft, Willa and Saadia discussing their mothers' lives and how they wanted their own lives to be different.
In a way, the first version I wrote is Saadia in another hundred years, and the second version is Saadia fifty-five years ago, at 17, so having put the time into them doesn't feel like a total waste.