Leo Stepanovich Demidov is an agent with the MGB.
That acronym stood for the Ministry of State Security, an organization in the Soviet Union government responsible for both espionage on other countries and counter-espionage against foreign operatives working in Russia. There were other uses for the men and women who worked in the department but the one that Demidov is mostly involved with, looking into criminal activity, does not exist because obviously in a perfect society such as provided by the Politboro, there is no need of crime. Murderers do not commit murders so there is no need for people like Demidov to hunt them down.
"He'd never intended to join the State Security Department; the career had grown out of his military service. During the Great Patriotic War he'd been recruited for a special forces unit, OMSBON-the Independent Motor-rifle Brigade for Special Tasks. The third and fourth battalions of this unit had been selected from the Central Institute of Physical Culture where he'd been a student. Handpicked for athleticism and physical prowess, they were taken to a training camp at Mytishchi, just north of Moscow, where they were taught close combat, weapons training, low-altitude parachuting, and the use of explosives. The camp belonged to the NKVD, as the secret police was known before State Security became the MGB. The battalions came under the direct authority of the NKVD, not the military, and the nature of their missions reflected this. Sent behind enemy lines, destroying infrastructure, collecting information, carrying out assassinations, they were clandestine raiders."
Demidov liked that kind of work because it meant independence in his operations but with the successes that he had, he also got notoriety which he did not want, and with that came the attention of the NKVD and the 'invitation' to work for them, just shortly before it would be reorganized into the MGB.
The adventures that Demidov is forced to take part in will find him in different parts of the country with different situations, most not for the better, because sometimes in the bizarre world of the Soviet Union, the only thing worse that failure is success.