HHhH is a brilliant novel. As Janet says, one reason it's so good is that it questions, among other things, the whole idea of how to write an historical novel. Its asides are part of its metafictional approach.
Did you read it in the original French, Janet? I can't read French but I thought the English translation by Sam Taylor was excellent.
Hi Libby, I apologise for answering this so late. I was in a bit of a work-panic when I saw it; I should have just stopped and answered you. I read the book in the English translation because I read it in connection with my own novel. Heydrich makes an appearance there, and it has asides to readers too, although of a very different kind. I’d love to read HHhH in French – whether I ever do is another question. But I think Laurent Binet is brilliant. He’s written alternative history, you know, and it also received a prestigious prize from the super-critical French – not that I’ve read that either.