10 Real Life Happy Endings That Became Disturbing Movies

7. Zodiac (2007)

Based on Robert Graysmith’s 1986 book about the Zodiac Killer, who terrorised California in the late 1960s, David Fincher’s true crime thriller is a meticulously authentic and powerful movie, with career-best performances from Jake Gyllenhaal as Graysmith, Robert Downey Jnr as journalist Paul Avery and Mark Ruffalo as police inspector Dave Toschi.

Like Jack The Ripper, the Zodiac wrote letters taunting press, police and public: like the Ripper, the Zodiac was never identified. For Graysmith, the Zodiac became an obsession that derailed his life. That’s at least partly what Fincher’s film is about: the compulsion to solve a puzzle, and how that compulsion can overwhelm everything.

We see Graysmith’s family leave; we see Toschi humiliated; we see Avery broken. But the Zodiac is never caught. Instead, Fincher caps the movie by detailing the circumstantial evidence pointing to suspect Arthur Leigh Allen.

He was free to do so because Allen, a convicted paedophile with no family or friends, had died in 1992: killer or not, such a man wasn’t going to have anyone in his corner. Regardless, the film’s narrative is as open-ended as the Zodiac investigation itself: unsolved, the case remains open to this day.

But all of this misses one crucial point. His confirmed slayings amounted to seven people over ten months. Everything we know about serial killers suggests a pattern of escalation - but just like Jack The Ripper, the Zodiac simply stopped.

Why? There’s only one likely answer. The Zodiac Killer died while they were all looking for him. There’s your happy ending.