It's 1982 and 7 people including a child are dead after taking Tylenol laced with cyanide. A paramedic and a nurse rush to piece together the truth.

Suspects emerge. A chilling letter and a leaked surveillance photo of a mystery man offer new clues. Could he be the person who poisoned the pills?

As police ramp up their manhunt for prime suspect James Lewis, the makers of Tylenol execute a multimillion-dollar PR campaign to save the brand.

Reporter Brad Edwards sets off to find James Lewis, the prime suspect in the Tylenol murders, and traces missed clues and chilling secrets of Lewis' past.

Decades pass. Victims' families remain haunted. Was the killer hiding in plain view all along? Could DNA technology crack this cold case?