Northern California, late 1960s. A masked killer taunts police and newspapers with coded letters, claiming victims and demanding his ciphers get front-page placement. He calls himself Zodiac. He's never caught.

Robert Graysmith was a cartoonist at the San Francisco Chronicle when the letters started arriving at his own newsroom. He became obsessed, chasing leads long after detectives moved on, cross-referencing suspects, timelines, and half-solved ciphers for years. The result was Zodiac, the book that turned his private obsession into the definitive account of the case — and later inspired David Fincher's film.

Some of Zodiac's ciphers stayed unsolved for over 50 years until amateur codebreakers cracked one in 2020. The case itself remains open. No one has ever been definitively convicted, despite decades of suspects, partial confessions, and DNA testing that keeps coming up inconclusive. Graysmith's book doesn't hand you a tidy ending — it hands you the obsession itself, and lets you decide who you believe.

If you want the case that still haunts cold-case detectives and true crime readers alike, grab a copy on Goodreads and see what Graysmith saw.