What do you do when a new character starts talking to you?
You transcribe, of course, and thank the Muse politely and hope this state of affairs will continue.
However, when the character starts by telling you her name – and it happens to be the name of the Greek Muse of Comedy – don’t be too surprised if she finds it screamingly funny to get you five chapters deep into a story told in first person and then to point out that she didn’t actually witness certain crucial scenes and what are you going to do about that?
The clatter, tinkle, crash you hear in the distance is the sound of rules breaking.
What did I do about it?
I let Thalia say “This next bit is out of order, because I didn’t actually hear about it until Ben and Ingrid got back and told me,” and then I shifted briskly into third-person narration from Ben’s point of view.
I inserted short third-person segments, carefully marked off by separators, where I needed the reader to know what the CIA case officer or the Babylonian turtle mage is thinking or what the murderous math student is doing.
And in other places I took advantage of the fact that Thalia didn’t actually witness the action. The part where an enterprising robotics student connects the turtle’s severed (but still talkative) head to a robot snake body? I’m not sure how you’d go about that even if you could. It’s much easier to have Meadow Melendez stagger out of her lab saying, “I do not believe what I just did. It couldn’t have worked.”
There were a few more bits of fancy dancing required to get to the end of A Pocketful of Stars, but I think they all worked; at least, the beta readers didn’t complain that any of those brief shifts out of first person bothered them. So while I may have torn up the official rules of narration and scattered their scraps to the winds, at least I haven’t broken the major rule that Thou Shalt Not Throw Thy Reader Out Of The Story.
I really, really hope it all worked, because Thalia has led me into a multi-book series; I’ve already written books 2-4 and am currently mulling over an interesting new direction for book 5. And they’re all first-person.