The satire The Devil Never Sleeps is the first film adaptation of the novel by writer and playwright Petr Karvaš. This film also marks the beginning of Karvaš's long-standing creative collaboration with director Petr Solan. Solan, along with fellow debutant František Žáček, based the film on three of Karvaš's short stories: Smutný káder, Typický prípad, Veľkorysá kampaň. The film's content is unified by the work and personal problems of the main character, the young and timid clerk Cyril Kvasnička. While the film's situational comedy reflects the era of its creation, a sense of detachment and sarcasm becomes apparent in the second half. For example, it reveals the typical paranoia and vigilance of the regime, such as the suspicion of the sad cadre, and highlights the pervasive phraseology that contrasts the constantly idealized reality with the lived experience.