Narrative setup before first frame — character history conveyed through implication only. Fincher deploys this systematically: we already know who arrives before they appear.
You're in the edit suite and realize: the audience already knows this character before they even speak. That's prehistory — not the geological era, but the invisible backstory of a role that you, as the director or editor, build before the first shot. Fincher does this masterfully: in Gone Girl, we already know who Nick Dunne is, what cracks lie in his marriage, before we even see him. This information doesn't come from exposition-heavy dialogue, but from editing, music, scene selection, and timing — everything works to draw a psychological profile.
On set, this functions through directorial decisions: you choose which scenes to shoot and in what order to show them. A character enters a room — but beforehand, we saw them in the car, hesitating before getting out. We read their face in close-ups. We already know they are afraid or lying, even though they haven't said anything yet. That's prehistory: the montage of details that reveal an internal state.
In the edit, this becomes concrete: you work with parallel editing, with flashbacks, with voice-overs that play out earlier than the visual action, with music that psychologically anticipates a character. When your protagonist speaks for the first time, the audience should already have a partial insight into their inner life. That's more efficient than exposition — and less sensational. It creates depth of field in characterization, not just spatial depth.
Practically, this means: before shooting, consider what non-verbal information you're conveying about a character before it becomes relevant. What glances? What movement patterns? What interactions with their environment? That's your tool for building prehistory — and it costs you nothing extra. It's pure directorial strategy. Fincher uses it because it builds trust: the audience doesn't feel lectured, they feel intelligent.