These men are hopelessly hooked on the buzz, and we watch how they are affected. At first, Gyllenhaal's stiff body language suggests a bashful persona, but he becomes progressively hyper as his fascination with the Zodiac grows. On the other hand, Downey's Avery starts out as a fearless type, but he steadily succumbs to paranoia, which he tries to drown with alcohol and drugs.

Zodiac takes its sweet time familiarizing us with the clues, so that it's thrilling when they finally start to fall into place. A noted visual stylist, Fincher indulges in a few elegant touches - which reportedly included up to 70 takes for certain scenes). Watch for the dozen or so cameo roles, including Chloe Sevigny, Philip Baker Hall, Brian Cox - as lawyer Melvin Belli - Donal Logue and John Carroll Lynch.)

Spanning a period of about 22 years, from 1969 until 1991, the rather long story manages to be an absorbing and fulfilling experience. Even though it lacks a neatly resolved ending (even in real life, the Zodiac case remains unsolved), overall, the film works. The storyline is peppered with humour, and while the film may lack a sense of who the killer was, Zodiac provides a dazzling narrative that grips you by the throat and doesn't let go.