Gone Girl: 10 Things That Are Different in the Movie

Instead of killing Amy, Nick begins to write a tell-all book, called Psycho B*tch. At the same time, Amy starts working on her own memoir, Amazing. It's a crucial part of the ending because Amy soon realizes Nick's book could ruin everything. That's why Amy impregnates herself with Nick's frozen sperm sample. She tells him she's expecting the day he gives her his finished manuscript.