Following several years of detours, “The Curious Case of Benjamin Button,” “The Social Network,” David Fincher went back to one of his bread and butter obsessions, serial killers, and the procedural film with Netflix’s series “Mindhunter.” In a way riffing on things he had already done in “Zodiac,” “Mindhunter” was a continuation of his preoccupations with fixation, through the lens of serial killers, but reverse-engineered, by those that try and catch and understand them: the FBI. A terrifically engrossing series, “Mindhunter,” ran for two seasons on Netflix, but a little after season two was done, the series was put on hold, and then seemed to die a slow death when casting options expired.

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Sources close to the project told us that “Mindhunter” season two was likely done nearly a year before it aired, because of a fatigued Fincher, but I wanted to see what would happen. I was told by the end of shooting season two, Fincher was “exhausted with a very lengthy shoot on location away from home,” aka Pittsburgh.

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And in a new interview with Vulture discussing Fincher’s new upcoming Netflix film “Mank,” the filmmaker echoed those sentiments about why “Mindhunter” folded. The director also suggested that he ended up pulling defacto double duty and was working 90-hour weeks because there was no active showrunner on the series.

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“We had done the first season of Mindhunter without a showrunner, with me pinch-hitting on a week-by-week basis,” he explained. “We started getting scripts for the second season, and I ended up looking at what was written and deciding I didn’t like any of it. So we tossed it and started over. I brought in Courtenay Miles, an AD I’d worked with who wanted to write, and she ended up co-showrunning Mindhunter. But it’s a 90-hour workweek. It absorbs everything in your life. When I got done, I was pretty exhausted, and I said, ‘I don’t know if I have it in me right now to break season three.’”

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Fincher spoke about “Mindhunter” being all-consuming and having to relocate from Los Angeles to Pittsburgh. “We lived there for almost three years. Not year in, year out, but we spent probably six or seven months a year over three years. We had an apartment there, and a car. Mindhunter was a lot for me.”

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Asked if “Mindhunter” was definitely over, Fincher said that seemed likely. “I think probably. Listen, for the viewership that it had, it was an expensive show. We talked about ‘Finish ‘Mank’ and then see how you feel,” but I honestly don’t think we’re going to be able to do it for less than I did season two. And on some level, you have to be realistic about dollars have to equal eyeballs.”

Given cast options have expired, would need to be redone, and schedules would need to be figured out all over again from scratch, it’s pretty obvious the show is already over. “Mindhunter” may be done, but it’s at least up there on Netflix forever, and if you haven’t seen it, you should rectify that immediately. Fincher’s next project, the black-and-white “Mank,” about the making of “Citizen Kane” will premiere on Netflix on December 4 and should be in some limited theaters before that in November.