The Other Emily - Die Doppelgängerin: Thriller

The revelation about Emily kept me on the edge, but I wonder what the author envisioned as the core mystery behind her character.

The unsettling atmosphere made me question what was real versus imagined. I'm curious how much of that was intentional on Koontz's part.

Switching viewpoints added layers to the suspense, but I'm interested in whether this was planned from the start or evolved during writing.