Anything he was going to say, anything he had been thinking about was wiped away immediately when he saw the book that peeked out of her bag. Without thinking about it, on pure instinct, he reached one of his hands toward his wrist -- only to be reminded that he hadn't brought any of the necklaces or bracelets Annie had made him with him here. Right. Gone before the quell.
Finnick had never thought about seeking out their source materials, whether book or movie. In fact, he had barely thought about the fact that they were supposed to be from sort of fictional world unless someone brought it up to them -- something he never knew how to react to.
So he was unprepared for even the sight of it. He and Katniss had never discussed it, let alone whether or not they would actually read anything. He had thought they had been on the same page there, but he was, evidently and obviously, quite wrong about that.
Even he didn't have a clever quip to cover about what had just happened. Instead, he just looked up at her, waiting.