Ratajkowski will play Andie, a college student who's having an affair with Affleck's Nick Dunne. Of course, he's married to Rosamund Pike's Amy Dunne, and when Amy goes missing the affair begins to look like a motive for Nick to murder his wife.
The film also features Neil Patrick Harris (How I Met Your Mother) as Amy's high school boyfriend Desi, Tyler Perry (I Can Do Bad All By Myself) as his defence attorney and Kim Dickens (The Blind Side) and Patrick Fugit (We Bought A Zoo) as police detectives. Big screen newcomer Carrie Coon plays Nick's twin sister (even though she's almost ten years younger than Affleck, clearly close enough in Hollywood terms).
Gillian Flynn adapted the screenplay from her own novel, and shooting starts this autumn. Look out for Gone Girl sometime late next year.