The Enemy clearly can't be reasoned with. Are there any (otherwordly or human) enemies in place that can be reasoned with at the moment in the Iridescent Sun storyline?
I'm just curious; I have a slightly Doctor-Who-ish sequence that's budding slowly in my mind, and which would hinge on there being an antagonist close by that could be reasoned with.
It might also establish some slightly (or even very!) disturbing things about Lucas as a character. She IS a good person, sure, but she, like anyone else, has character flaws (and, incidentally, I hope like Hell I'm not making her a Mary Sue). Lucas is vengeful, unfettered by moral or other concerns when it comes to preserving her own freedom or that of others, etc., and this might - among other things - showcase the "less pretty" side of her.
Now, that's NOT to say I'm intent on using it "at all costs". I'm not gonna force it into the story if it doesn't work and I'm not about to add it unless it REALLY adds to the story, and there are quite a lot of characters at the moment, so I'm not gonna insert a new antagonist unless it's REALLY a good idea to do so.