Pretty interesting. Structuring the book as a series of conversations, log entries, and so forth allows the reader to participate in discovering what's going on. And it's an interesting story.

Spoiler

The narrator/interlocutor is never identified, as far as I know, but seems to be some sort of special agent.

I've already borrowed e-book #2 ([b:Waking Gods|30134847|Waking Gods (Themis Files, #2)|Sylvain Neuvel|https://images.gr-assets.com/books/1462736382s/30134847.jpg|50566357]) from a nearby library, so clearly the story is compelling enough to keep me going.