A serial killer is terrorising the people of Bologna and rookie Detective Inspector Grazia Negro is determined to solve the case. She only has one witness who can identify the killer - and he is blind. Simone spends his nights listening to Chet Baker and scanning the radio waves of the city, eavesdropping on other people's lives.

He imagines what people are like - based on the 'colour' of their voice - and his acute hearing sets alarm bells ringing when he tunes in to the killer. Together Simone and Negro are the only people able to stop the killer, before he closes in on Simone. From the diverse perspectives of the detective, the blind Simone and the killer, Lucarelli, master of Italian noir, weaves a gripping thriller.