A strange case came to the attention of prosecutor's office investigator Arkhip Shchukin: someone in black shot seven times at young businessman Valentin Samoilov almost point-blank and... did not kill him! It soon turns out that first Valentin’s grandfather and then Valentin’s father were shot with the same pistol... What is this? Vendetta in Russian? Shchukin assigned the main role in the investigation to the study of archives - and, turning to the tragic events of half a century ago, he was not mistaken. Making smart moves one after another, he figured out who was shooting. And... left the criminal free! What is this? Another mystery? Arbitrariness of an investigator exceeding his authority? Or is there a false trail again - which means the search will have to start all over again?.. Previously, the book was published under the title “White Cat in a Bright Room”