Zodiac

The Zodiac killings are the subject, but the film is about the people who could not stop working the case — a cartoonist, a reporter and two detectives, losing careers, marriages and years to a puzzle that was never solved.

Fincher researched it obsessively, shot huge numbers of takes, and built a procedural that refuses every satisfaction the genre normally supplies. There is no confrontation and no confession. Leads simply run out, jurisdictions fail to share files, handwriting experts disagree, and the trail goes cold in the middle of the film with ninety minutes still to run.

That refusal is why it lasts. Most serial killer films are about catching someone; this one is about what obsession does to you when the answer never arrives.