On September 29, 1982, 12-year old Mary Kellerman was suffering from a cold. To sooth her symptoms, she took some Tylenol. Within 4 hours, she was pronounced dead. Ultimately, 6 other people would mysteriously collapse after taking the common over-the-counter drug. Eventually the investigation would link the deaths and uncover a sinister truth: Someone had tampered with the Tylenol bottles, lacing them with potassium cyanide.

Special guest Sohaib is back, and episode 7 explores the tragic story of the Chicago Area Tylenol Poisonings.