Working from a brilliant screenplay by Steven Zaillian, Fincher's take on the story focuses more on what I've come to understand is really a classic locked room mystery in the Agatha Christie mode — in the case of the murder / disappearance of Harriet Vanger, the locked room is an island whose sole entry point is blocked by
an overturned tanker truck — that is concealed within a study of unlimited misogyny and sidetracked into the discovery of a serial killer.