If you own the film on physical media, the Director's Cut typically includes several built-in subtitle tracks:
If you have a digital file and need external subtitles, you can find them on dedicated repositories: Alternate versions - Zodiac (2007) - IMDb zodiac directors cut subtitles
The film’s climactic sequence—Robert Graysmith (Jake Gyllenhaal) visiting the basement of Bob Vaughn (Charles Fleischer)—is famously ambiguous. In the Director’s Cut, the final exchange is altered via subtitle timing. Vaughn says, “I’m not the Zodiac. But if I was, would I tell you?” In the theatrical cut, the subtitle fades with the line. If you own the film on physical media,