In our presentation we would like to demonstrate how the staff of the Hungarian Prison Service has protected and continues to protect against an invisible ‘enemy’”, a human epidemic caused by the COVID–19 virus. We have been fighting this battle under the continuous guidance of the Operational Body established at the Hungarian Prison Service Headquarters (hereinafter: the Body). We describe what immediate, preventive measures were put in place by the Body to prevent coronavirus infection from entering the prisons and other penitentiary facilities. We present how the spreading of the infection was prevented after the appearance of the infection in the prisons with the start of the second wave, and furthermore what tools and methods did we use to protect ourselves during the period of the third wave. How the life of the Prison Service changed overnight, what additional burdens did the control of the human epidemic meant for the staff, how the epidemic affected the daily life of the prisoners, their admission, their employment, the inmates’ contact with their relatives and contact persons, and their transportation and escort to trials.