One device frequently used by writers of mystery fiction is the intrusion of some force to obstruct the investigator's job, which sometimes takes the form of a powerful adversary or a repressive political system.
In Martin Cruz Smith's "Gorky Park," for example, a Moscow homicide cop finds his efforts stifled by the Soviet system. Philipp Kerr's series of novels featuring private eye Bernie Gunther, initially set in prewar Berlin, show the near-impossibility of impartial investigations of cases due to pressures from Nazi doctrinaires.
In "City of Veils," Zoe Ferraris' second novel set in Jeddah, Saudi Arabia, the protagonists must circumvent a different set of predicaments: social restrictions that prohibit men from talking to women with whom they are not related.