A novel about the operatives of the Moscow Criminal Investigation Department (MUR), about their difficult and dangerous work in fighting crime. The events take place in the first postwar year, 1945. Officer Sharapov, a former regimental scout, joins the MUR to protect and guard what the people defended during the war years. As part of an оперативная group led by Captain Zheglov, he takes part in exposing and neutralizing the dangerous gang known as the “Black Cat.”