Franco Arno is a blind man who works as a crossword puzzle writer and lives with his young niece. One evening as he strolls down the street, he overhears two men having an odd conversation in a car that is parked in front of a medical facility where genetic experiments are being conducted. The institute is broken into that same night, and a guard is killed. With the aid of journalist Carlo Giordani, Arno decides to look into the matter.
The two journalists become the killer’s targets as they work to solve a string of murders linked to a pharmaceutical company’s covert studies.