In San Francisco, during the 1970s, a journalist from a local newspaper and a cartoonist become obsessed with an enigmatic killer who signs as "Zodiac." This mysterious criminal terrorizes the city, leaving cryptic clues and challenging the police with his letters and symbols. As the murders increase, the two men plunge into a dark world of speculation and theories, blurring the line between rationality and madness.
On the other hand, a police investigator finds himself trapped in a race against time as he tries to solve the case before the killer can strike again. The tension escalates as the Zodiac seems to anticipate every move of the law. The main characters, each grappling with their own demons, are drawn into a labyrinth of information and clues, affecting their personal and professional relationships.
Obsession becomes corrosive; the lives of those involved in the hunt for the killer grow increasingly complex and tumultuous. The investigation progresses slowly, leaving the public wondering if justice will ever be served. In an environment where fear and paranoia take over everyday life, the true horror lies not only in the figure of the killer, but in the emotional and psychological impact his presence leaves on society. The story explores the cost of obsession and the quest for truth.