Otage de la nuit

The layered storytelling added a spooky depth to the book. I'm curious whether this was a plan from the start or developed during writing.

The book managed to be creepy without crossing into too dark territory, which is hard to pull off. How did the author decide where to draw that line?

The house felt like a character itself, full of secrets and magic. I wonder what inspired the design of this spooky yet captivating place.