Based on the true story of a serial killer who terrified the U.S.’s San Francisco Bay Area and taunted authorities in four jurisdictions with his ciphers and letters for decades. Hunting down the hunter would become an obsession for four men, an obsession that would turn them into ghosts of their former selves, their lives built and destroyed by the killer’s endless trail of clues. He publicly claimed 13 victims, then two dozen more. Police pinned him with seven, five dead. The rampage of a madman who has never been caught; the elusive cipher slayer who gripped the nation in fear, America’s very own Jack the Ripper. The true body count may never be known. One thing is certain: That count includes the living.